diff --git a/include/client/state/GameState.h b/include/client/state/GameState.h
index 6d4f5d2..8e4acde 100644
--- a/include/client/state/GameState.h
+++ b/include/client/state/GameState.h
@@ -9,12 +9,12 @@ namespace client {
 
 class GameState : public ClientState {
   private:
-	std::shared_ptr<game::World> m_World;
+	game::WorldPtr m_World;
 	sim::ClientSimulation m_Simulation;
 	float m_CurrentLerp;
 
   public:
-	GameState(Client& a_Client, const std::shared_ptr<game::World>& a_World, std::uint64_t a_StepTime);
+	GameState(Client& a_Client, const game::WorldPtr& a_World, std::uint64_t a_StepTime);
 	~GameState() {}
 
 	virtual void Update(float a_Delta) override;
@@ -23,6 +23,10 @@ class GameState : public ClientState {
 		return m_CurrentLerp;
 	}
 
+	game::WorldPtr GetWorld() const {
+		return m_World;
+	}
+
 	virtual void Handle(const protocol::packets::LockStepsPacket& a_LockStep) override;
 	virtual void Handle(const protocol::packets::LockStepResponsePacket& a_LockStep) override;
 };
diff --git a/include/client/state/LobbyState.h b/include/client/state/LobbyState.h
new file mode 100644
index 0000000..5b4de28
--- /dev/null
+++ b/include/client/state/LobbyState.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <client/ClientState.h>
+#include <td/game/World.h>
+#include <td/simulation/ClientSimulation.h>
+
+namespace td {
+namespace client {
+
+class LobbyState : public ClientState {
+  private:
+	std::shared_ptr<game::World> m_World;
+  public:
+	LobbyState(Client& a_Client);
+	~LobbyState();
+
+	virtual void Update(float a_Delta) override;
+
+	virtual void Handle(const protocol::packets::WorldHeaderPacket& a_Packet) override;
+	virtual void Handle(const protocol::packets::WorldDataPacket& a_Packet) override;
+};
+
+}  // namespace client
+}  // namespace td
diff --git a/include/client/state/LoggingState.h b/include/client/state/LoggingState.h
index 1a7e5ec..8a5e4b2 100644
--- a/include/client/state/LoggingState.h
+++ b/include/client/state/LoggingState.h
@@ -12,7 +12,7 @@ class LoggingState : public ClientState {
 	LoggingState(Client& a_Client, const std::string& a_PlayerName);
 	~LoggingState();
 
-	virtual void Update(float a_Delta) override {}
+	virtual void Update(float a_Delta) override;
 
 	virtual void Handle(const protocol::packets::PlayerJoinPacket& a_Packet) override;
 	virtual void Handle(const protocol::packets::LoggingSuccessPacket& a_Packet) override;
diff --git a/include/server/IServerSocket.h b/include/server/IServerSocket.h
index 0dc28bf..fb90e7a 100644
--- a/include/server/IServerSocket.h
+++ b/include/server/IServerSocket.h
@@ -12,8 +12,8 @@ class IServerSocket {
 	using PlayerPacketHandlerType = std::unique_ptr<protocol::PacketHandler>(PlayerID);
 	using PlayerPacketHandler = std::function<PlayerPacketHandlerType>;
 
-	utils::Signal<PlayerID, const PlayerInfo&> OnPlayerJoin;
-	utils::Signal<PlayerID> OnPlayerLeave;
+	utils::Signal<PlayerID> OnPlayerConnect;
+	utils::Signal<PlayerID> OnPlayerDisconnect;
 	utils::Signal<PlayerID, const protocol::PacketBase&> OnReceive;
 
 	void Send(PlayerID a_PlayerId, const protocol::PacketBase& a_Packet);
diff --git a/include/server/PlayerManager.h b/include/server/PlayerManager.h
index fb1b5fb..0801ce6 100644
--- a/include/server/PlayerManager.h
+++ b/include/server/PlayerManager.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <td/misc/Signal.h>
 #include <td/protocol/packet/Packets.h>
 
 namespace td {
@@ -13,6 +14,9 @@ class PlayerManager {
 	std::shared_ptr<IServerSocket> m_Socket;
 
   public:
+	utils::Signal<PlayerID, const PlayerInfo&> OnPlayerJoin;
+	utils::Signal<PlayerID> OnPlayerLeave;
+
 	PlayerManager(const std::shared_ptr<IServerSocket>& a_Socket);
 	~PlayerManager();
 
@@ -20,20 +24,19 @@ class PlayerManager {
 	PlayerInfo GetPlayer(PlayerID a_Player);
 
   private:
+	void Disconnect(PlayerID a_Player);
+	
 	class ConnectionHandler : public protocol::PacketHandler {
 	  private:
-		std::map<PlayerID, PlayerInfo>& m_Players;
-		IServerSocket& m_Socket;
+		PlayerManager& m_PlayerManager;
 		PlayerID m_Player;
 
 	  public:
-		ConnectionHandler(std::map<PlayerID, PlayerInfo>& a_Players, IServerSocket& a_Socket, PlayerID a_Player);
+		ConnectionHandler(PlayerManager& a_PlayerManager, PlayerID a_Player);
 		~ConnectionHandler() = default;
 
 		virtual void Handle(const protocol::packets::PlayerLoginPacket& a_Packet) override;
 		virtual void Handle(const protocol::packets::DisconnectPacket& a_Packet) override;
-
-		static void Disconnect(std::map<PlayerID, PlayerInfo>&, IServerSocket& m_Socket, PlayerID m_Player);
 	};
 };
 
diff --git a/include/server/Server.h b/include/server/Server.h
index ea78fb1..ef5033e 100644
--- a/include/server/Server.h
+++ b/include/server/Server.h
@@ -20,6 +20,10 @@ class Server : public StateMachine<Server, void, float> {
 
 	virtual void Update(float a_Delta);
 
+	const PlayerManager& GetPlayers() const {
+		return m_Players;
+	}
+
 	friend class ServerState;
 };
 
diff --git a/include/server/state/LobbyState.h b/include/server/state/LobbyState.h
index e4ba6be..f8996eb 100644
--- a/include/server/state/LobbyState.h
+++ b/include/server/state/LobbyState.h
@@ -10,9 +10,11 @@ class LobbyState : public ServerState {
   private:
 	std::shared_ptr<game::World> m_World;
   public:
-	LobbyState(Server& a_Server, const std::shared_ptr<game::World>& a_World);
+	LobbyState(Server& a_Server);
 	~LobbyState() {}
 
+	virtual void OnPlayerJoin(PlayerID a_Id, const td::PlayerInfo& a_Info) override;
+
 	virtual void HandlePacket(PlayerID a_Id, const protocol::PacketBase& a_Packet) override;
 	virtual void Update(float a_Delta) override;
 };
diff --git a/include/td/common/StateMachine.h b/include/td/common/StateMachine.h
index 1bf0fb4..9669b11 100644
--- a/include/td/common/StateMachine.h
+++ b/include/td/common/StateMachine.h
@@ -1,7 +1,7 @@
 #pragma once
 
 #include <cassert>
-#include <memory>
+#include <td/misc/Signal.h>
 
 namespace td {
 
@@ -16,7 +16,7 @@ class StateMachine {
 		virtual TReturn Update(TArgs... args) = 0;
 
 		template <typename T, typename... Args>
-		T* ChangeState(Args&&... args) {
+		T* ChangeState(Args... args) {
 			return m_StateMachine.template ChangeState<T>(std::forward<Args>(args)...);
 		}
 
@@ -24,18 +24,25 @@ class StateMachine {
 		TDerived& m_StateMachine;
 	};
 
+	utils::Signal<State&> OnStateChange;
+
 	StateMachine() {}
 	StateMachine(StateMachine&&) = default;
 	virtual ~StateMachine() {}
 
 	virtual TReturn Update(TArgs... args) {
 		assert(m_State && "You must change state at least once before updating !");
-		return m_State->Update(args...);
+		return m_State->Update(std::forward<TArgs>(args)...);
 	}
 
 	template <typename T, typename... Args>
-	T* ChangeState(Args&&... args) {
-		m_State = std::make_unique<T>(static_cast<TDerived&>(*this), std::forward<Args>(args)...);
+	T* ChangeState(Args... args) {
+		auto* currentState = m_State.get();
+		auto newState = std::make_unique<T>(static_cast<TDerived&>(*this), std::forward<Args>(args)...);
+		// This allows chaining
+		if (m_State.get() == currentState)
+			m_State = std::move(newState);
+		OnStateChange(*m_State);
 		return static_cast<T*>(m_State.get());
 	}
 
diff --git a/include/td/display/DisplayState.h b/include/td/display/DisplayState.h
index 0ad0790..5190945 100644
--- a/include/td/display/DisplayState.h
+++ b/include/td/display/DisplayState.h
@@ -2,8 +2,10 @@
 
 #include <td/display/Display.h>
 #include <td/misc/SlotGuard.h>
+#include <client/ClientState.h>
 
 namespace td {
+
 class DisplayState : public Display::State, private utils::SlotGuard {
   public:
 	DisplayState(Display& a_Display);
@@ -13,4 +15,5 @@ class DisplayState : public Display::State, private utils::SlotGuard {
 	virtual void OnAspectRatioChange(float a_Ratio) {}
 	virtual void OnKeyDown(SDL_Keycode a_Key) {}
 };
+
 }  // namespace td
diff --git a/include/td/game/World.h b/include/td/game/World.h
index 9177cd6..5a953f9 100644
--- a/include/td/game/World.h
+++ b/include/td/game/World.h
@@ -33,6 +33,9 @@ class World {
 	bool LoadMap(const protocol::pdata::WorldHeader& worldHeader);
 	bool LoadMap(const protocol::pdata::WorldData& worldData);
 
+	protocol::packets::WorldHeaderPacket GetPacketHeader() const;
+	protocol::packets::WorldDataPacket GetPacketData() const;
+
 	bool LoadMapFromFile(const std::string& fileName);
 	bool SaveMap(const std::string& fileName) const;
 
diff --git a/src/client/Client.cpp b/src/client/Client.cpp
index a933e89..a843f60 100644
--- a/src/client/Client.cpp
+++ b/src/client/Client.cpp
@@ -6,7 +6,7 @@ namespace td {
 namespace client {
 
 Client::Client(const std::shared_ptr<IClientSocket>& a_Socket, const std::string& a_PlayerName) : m_Socket(a_Socket), m_Players(a_Socket) {
-	ChangeState<LoggingState>(a_PlayerName);
+	// ChangeState<LoggingState>(a_PlayerName);
 }
 
 void Client::SendPacket(const protocol::PacketBase& a_Packet) {
diff --git a/src/client/PlayerManager.cpp b/src/client/PlayerManager.cpp
index 8403874..a7da9c3 100644
--- a/src/client/PlayerManager.cpp
+++ b/src/client/PlayerManager.cpp
@@ -10,7 +10,7 @@ namespace client {
 PlayerManager::PlayerManager(const std::shared_ptr<IClientSocket>& a_Socket) : m_Socket(a_Socket) {
 	a_Socket->OnReceive.Connect(std::bind(&PlayerManager::HandleBase, this, std::placeholders::_1));
 	OnPlayerJoin.Connect([this](const PlayerInfo& a_Player){
-		std::cout << "[Client " << this << "] " << a_Player.m_PlayerName << "(" << +a_Player.m_PlayerId << ") joined !\n";
+		std::cout << "[Client " << this << "] " << a_Player.m_PlayerName << " joined !\n";
 	});
 	OnPlayerLeave.Connect([this](const PlayerID a_Player){
 		std::cout << "[Client " << this << "] " << GetPlayer(a_Player).m_PlayerName << "(" << +a_Player << ") left !\n";
diff --git a/src/client/state/LobbyState.cpp b/src/client/state/LobbyState.cpp
new file mode 100644
index 0000000..a67c3de
--- /dev/null
+++ b/src/client/state/LobbyState.cpp
@@ -0,0 +1,24 @@
+#include <client/state/LobbyState.h>
+
+#include <client/state/GameState.h>
+
+namespace td {
+namespace client {
+
+LobbyState::LobbyState(Client& a_Client) : ClientState(a_Client), m_World(std::make_shared<game::World>()) {}
+
+LobbyState::~LobbyState() {}
+
+void LobbyState::Handle(const protocol::packets::WorldHeaderPacket& a_Packet) {
+	m_World->LoadMap(*a_Packet);
+}
+
+void LobbyState::Handle(const protocol::packets::WorldDataPacket& a_Packet) {
+	m_World->LoadMap(*a_Packet);
+	ChangeState<GameState>(m_World, STEP_TIME);
+}
+
+void LobbyState::Update(float a_Delta) {}
+
+}  // namespace client
+}  // namespace td
diff --git a/src/client/state/LoggingState.cpp b/src/client/state/LoggingState.cpp
index ee3d43d..9fccb79 100644
--- a/src/client/state/LoggingState.cpp
+++ b/src/client/state/LoggingState.cpp
@@ -1,6 +1,6 @@
 #include <client/state/LoggingState.h>
 
-#include <iostream>
+#include <client/state/LobbyState.h>
 
 namespace td {
 namespace client {
@@ -9,6 +9,9 @@ LoggingState::LoggingState(Client& a_Client, const std::string& a_PlayerName) :
 	SendPacket(td::protocol::packets::PlayerLoginPacket(a_PlayerName));
 }
 
+void LoggingState::Update(float a_Delta) {
+}
+
 LoggingState::~LoggingState() {}
 
 void LoggingState::Handle(const protocol::packets::PlayerJoinPacket& a_Packet) {
@@ -16,7 +19,7 @@ void LoggingState::Handle(const protocol::packets::PlayerJoinPacket& a_Packet) {
 }
 
 void LoggingState::Handle(const protocol::packets::LoggingSuccessPacket& a_Packet) {
-	// TODO: switch state
+	ChangeState<LobbyState>();
 }
 
 }  // namespace client
diff --git a/src/server/IServerSocket.cpp b/src/server/IServerSocket.cpp
index 5fe5c2b..a66429e 100644
--- a/src/server/IServerSocket.cpp
+++ b/src/server/IServerSocket.cpp
@@ -19,10 +19,11 @@ void IServerSocket::UnregisterHandler(const PlayerPacketHandler& a_Handler) {
 void IServerSocket::OnConnectPeer(PeerID a_PeerId) {
 	// here, the client is not a player yet (we need to wait for auth)
 	m_Ids.AddConnection(a_PeerId);
+	OnPlayerConnect(m_Ids.GetPlayerId(a_PeerId));
 }
 
 void IServerSocket::OnDisconnectPeer(PeerID a_PeerId) {
-	OnPlayerLeave(m_Ids.GetPlayerId(a_PeerId));
+	OnPlayerDisconnect(m_Ids.GetPlayerId(a_PeerId));
 	m_Ids.RemovePeer(a_PeerId);
 }
 
diff --git a/src/server/PlayerManager.cpp b/src/server/PlayerManager.cpp
index 1c56850..ae273c0 100644
--- a/src/server/PlayerManager.cpp
+++ b/src/server/PlayerManager.cpp
@@ -6,48 +6,52 @@
 namespace td {
 namespace server {
 
-PlayerManager::ConnectionHandler::ConnectionHandler(
-	std::map<PlayerID, PlayerInfo>& a_Players, IServerSocket& a_Socket, PlayerID a_Player) :
-	m_Players(a_Players), m_Socket(a_Socket), m_Player(a_Player) {}
+PlayerManager::ConnectionHandler::ConnectionHandler(PlayerManager& a_PlayerManager, PlayerID a_Player) :
+	m_PlayerManager(a_PlayerManager), m_Player(a_Player) {}
 
 void PlayerManager::ConnectionHandler::Handle(const protocol::packets::PlayerLoginPacket& a_Packet) {
 	PlayerInfo pInfo{m_Player, a_Packet->m_PlayerName};
 
-	std::vector<PlayerInfo> players;
-	players.reserve(m_Players.size());
-	for (auto& [id, player] : m_Players) {
-		players.push_back(player);
+	auto& socket = *m_PlayerManager.m_Socket;
+	auto& players = m_PlayerManager.m_Players;
+
+	std::vector<PlayerInfo> playerInfos;
+	playerInfos.reserve(players.size());
+	for (auto& [id, player] : players) {
+		playerInfos.push_back(player);
 	}
 
-	m_Socket.Send(m_Player, protocol::packets::LoggingSuccessPacket(m_Player));
-	m_Socket.Send(m_Player, protocol::packets::PlayerListPacket(players));
-	m_Socket.Broadcast(protocol::packets::PlayerJoinPacket(pInfo));
+	socket.Send(m_Player, protocol::packets::LoggingSuccessPacket(m_Player));
+	socket.Send(m_Player, protocol::packets::PlayerListPacket(playerInfos));
+	socket.Broadcast(protocol::packets::PlayerJoinPacket(pInfo));
 
-	m_Players.emplace(m_Player, pInfo);
-	m_Socket.OnPlayerJoin(m_Player, pInfo);
+	players.emplace(m_Player, pInfo);
+	m_PlayerManager.OnPlayerJoin(m_Player, pInfo);
 	std::cout << "[Server] " << a_Packet->m_PlayerName << " joined !\n";
 }
 
 void PlayerManager::ConnectionHandler::Handle(const protocol::packets::DisconnectPacket& a_Packet) {
-	std::cout << "[Server] " << +m_Player << " wants to disconnect !\n";
-	Disconnect(m_Players, m_Socket, m_Player);
+	m_PlayerManager.Disconnect(m_Player);
 }
 
 PlayerManager::PlayerManager(const std::shared_ptr<IServerSocket>& a_Socket) : m_Socket(a_Socket) {
-	a_Socket->RegisterHandler(
-		[this](PlayerID a_PlayerId) { return std::make_unique<ConnectionHandler>(m_Players, *m_Socket, a_PlayerId); });
+	a_Socket->RegisterHandler([this](PlayerID a_PlayerId) { return std::make_unique<ConnectionHandler>(*this, a_PlayerId); });
+	a_Socket->OnPlayerDisconnect.Connect(std::bind(&PlayerManager::RemovePlayer, this, std::placeholders::_1));
 }
 
-void PlayerManager::ConnectionHandler::Disconnect(std::map<PlayerID, PlayerInfo>& a_Players, IServerSocket& a_Socket, PlayerID a_Player) {
-	a_Socket.Disconnect(a_Player);
-	a_Socket.Broadcast(protocol::packets::PlayerLeavePacket(a_Player));
-	a_Players.erase(a_Player);
+void PlayerManager::Disconnect(PlayerID a_Player) {
+	if (!m_Players.contains(a_Player))
+		return;
+	std::cout << "[Server] " << +a_Player << " wants to disconnect !\n";
+	m_Socket->Disconnect(a_Player);
+	m_Socket->Broadcast(protocol::packets::PlayerLeavePacket(a_Player));
+	m_Players.erase(a_Player);
 }
 
 PlayerManager::~PlayerManager() {}
 
 void PlayerManager::RemovePlayer(PlayerID a_Player) {
-	ConnectionHandler::Disconnect(m_Players, *m_Socket, a_Player);
+	Disconnect(a_Player);
 }
 
 PlayerInfo PlayerManager::GetPlayer(PlayerID a_Player) {
diff --git a/src/server/Server.cpp b/src/server/Server.cpp
index 9105691..6a8e284 100644
--- a/src/server/Server.cpp
+++ b/src/server/Server.cpp
@@ -2,10 +2,14 @@
 
 #include <chrono>
 
+#include <server/state/LobbyState.h>
+
 namespace td {
 namespace server {
 
-Server::Server(const std::shared_ptr<IServerSocket>& a_Socket) : m_Socket(a_Socket), m_Players(a_Socket), m_LastMspt(0) {}
+Server::Server(const std::shared_ptr<IServerSocket>& a_Socket) : m_Socket(a_Socket), m_Players(a_Socket), m_LastMspt(0) {
+	ChangeState<LobbyState>();
+}
 
 void Server::Update(float a_Delta) {
 	auto before = std::chrono::system_clock::now();
diff --git a/src/server/ServerState.cpp b/src/server/ServerState.cpp
index 12dd27c..552a4f7 100644
--- a/src/server/ServerState.cpp
+++ b/src/server/ServerState.cpp
@@ -8,8 +8,8 @@ namespace server {
 
 ServerState::ServerState(Server& a_Server) : Server::State(a_Server) {
 	Connect(m_StateMachine.m_Socket->OnReceive, std::bind(&ServerState::HandlePacket, this, std::placeholders::_1, std::placeholders::_2));
-	Connect(m_StateMachine.m_Socket->OnPlayerJoin, std::bind(&ServerState::OnPlayerJoin, this, std::placeholders::_1, std::placeholders::_2));
-	Connect(m_StateMachine.m_Socket->OnPlayerLeave, std::bind(&ServerState::OnPlayerLeave, this, std::placeholders::_1));
+	Connect(m_StateMachine.m_Players.OnPlayerJoin, std::bind(&ServerState::OnPlayerJoin, this, std::placeholders::_1, std::placeholders::_2));
+	Connect(m_StateMachine.m_Players.OnPlayerLeave, std::bind(&ServerState::OnPlayerLeave, this, std::placeholders::_1));
 }
 
 ServerState::~ServerState() {}
diff --git a/src/server/state/GameState.cpp b/src/server/state/GameState.cpp
index fdc6640..09cea6e 100644
--- a/src/server/state/GameState.cpp
+++ b/src/server/state/GameState.cpp
@@ -1,5 +1,6 @@
 #include <server/state/GameState.h>
 #include <server/state/GameStateHandler.h>
+#include <td/protocol/packet/PacketSerialize.h>
 
 #include <iostream>
 
@@ -7,7 +8,9 @@ namespace td {
 namespace server {
 
 GameState::GameState(Server& a_Server, const std::shared_ptr<game::World>& a_World) : ServerState(a_Server), m_World(a_World), m_Simulation(*m_World, STEP_TIME), m_Time(0) {
-	std::cout << "Switched to Game state !\n";
+	std::cout << "[Server] Switched to Game state !\n";
+	BroadcastPacket(a_World->GetPacketHeader());
+	BroadcastPacket(a_World->GetPacketData());
 	BroadcastPacket(m_Simulation.MakePacket());
 }
 
diff --git a/src/server/state/LobbyState.cpp b/src/server/state/LobbyState.cpp
index feac84d..e22ff6a 100644
--- a/src/server/state/LobbyState.cpp
+++ b/src/server/state/LobbyState.cpp
@@ -1,18 +1,60 @@
-#include <server/state/LobbyState.h>
 #include <server/state/GameState.h>
+#include <server/state/LobbyState.h>
 
 #include <iostream>
+#include <fstream>
+#include <td/protocol/packet/PacketSerialize.h>
+
+#include <sp/common/DataBuffer.h>
+#include <sp/extensions/Compress.h>
+#include <sp/io/MessageStream.h>
+#include <sp/io/StdIo.h>
 
 namespace td {
 namespace server {
 
-void LobbyState::HandlePacket(PlayerID a_Id, const protocol::PacketBase& a_Packet) {
+void Save(const protocol::PacketBase& header, const protocol::PacketBase& data) {
+	auto comp = std::make_shared<sp::ZlibCompress>();
 
+	std::ofstream fStream("test/tdmap.tdmap3");
+	auto out = std::make_shared<sp::StdOuput>(fStream);
+
+	sp::MessageStream<protocol::PacketFactory> stream(std::move(out), std::move(comp));
+
+	stream.WriteMessage(header, false);
+	stream.WriteMessage(data, false);
 }
 
-void LobbyState::Update(float a_Delta) {
-	m_StateMachine.ChangeState<GameState>(m_World);
+game::WorldPtr GetWorld() {
+	auto comp = std::make_shared<sp::ZlibCompress>();
+
+	std::ifstream fStream("test/tdmap.tdmap2");
+	auto out = std::make_shared<sp::StdInput>(fStream);
+
+	sp::MessageStream<protocol::PacketFactory> stream(std::move(out), std::move(comp));
+
+	auto header = stream.ReadConcreteMessage<protocol::packets::WorldHeaderPacket>();
+	auto data = stream.ReadConcreteMessage<protocol::packets::WorldDataPacket>();
+
+	auto w = std::make_shared<game::World>();
+
+	w->LoadMap(**header);
+	w->LoadMap(**data);
+
+	// Save(*header, *data);
+
+	return w;
 }
 
+LobbyState::LobbyState(Server& a_Server) : ServerState(a_Server) {}
+
+void LobbyState::HandlePacket(PlayerID a_Id, const protocol::PacketBase& a_Packet) {}
+
+void LobbyState::OnPlayerJoin(PlayerID a_Id, const td::PlayerInfo& a_Info) {
+	m_StateMachine.ChangeState<GameState>(GetWorld());
+}
+
+void LobbyState::Update(float a_Delta) {}
+
 }  // namespace server
 }  // namespace td
diff --git a/src/td/display/state/DebugWorldState.cpp b/src/td/display/state/DebugWorldState.cpp
index 607ea7e..d39e710 100644
--- a/src/td/display/state/DebugWorldState.cpp
+++ b/src/td/display/state/DebugWorldState.cpp
@@ -1,101 +1,69 @@
 #include <td/display/state/DebugWorldState.h>
 
 #include <chrono>
-#include <fstream>
 #include <iostream>
 
 #include <td/game/World.h>
-#include <td/protocol/packet/PacketSerialize.h>
 #include <td/protocol/packet/Packets.h>
 #include <td/render/renderer/EntityRenderer.h>
 #include <td/render/renderer/TowerRenderer.h>
 #include <td/render/renderer/WorldRenderer.h>
 
-#include <sp/common/DataBuffer.h>
-#include <sp/extensions/Compress.h>
-#include <sp/io/MessageStream.h>
-#include <sp/io/StdIo.h>
-
 #include <server/Server.h>
 #include <server/socket/FakeSocket.h>
-#include <server/state/GameState.h>
+#include <server/state/LobbyState.h>
 
 #include <client/Client.h>
 #include <client/socket/FakeSocket.h>
 #include <client/state/GameState.h>
+#include <client/state/LoggingState.h>
 
 #include <td/display/Display.h>
 #include <td/display/state/DebugWorldState.h>
 
 namespace td {
 
-void Save(const protocol::PacketBase& header, const protocol::PacketBase& data) {
-	auto comp = std::make_shared<sp::ZlibCompress>();
-
-	std::ofstream fStream("test/tdmap.tdmap3");
-	auto out = std::make_shared<sp::StdOuput>(fStream);
-
-	sp::MessageStream<protocol::PacketFactory> stream(std::move(out), std::move(comp));
-
-	stream.WriteMessage(header, false);
-	stream.WriteMessage(data, false);
-}
-
-game::WorldPtr GetWorld() {
-	auto comp = std::make_shared<sp::ZlibCompress>();
-
-	std::ifstream fStream("test/tdmap.tdmap2");
-	auto out = std::make_shared<sp::StdInput>(fStream);
-
-	sp::MessageStream<protocol::PacketFactory> stream(std::move(out), std::move(comp));
-
-	auto header = stream.ReadConcreteMessage<protocol::packets::WorldHeaderPacket>();
-	auto data = stream.ReadConcreteMessage<protocol::packets::WorldDataPacket>();
-
-	auto w = std::make_shared<game::World>();
-
-	w->LoadMap(**header);
-	w->LoadMap(**data);
-
-	// Save(*header, *data);
-
-	return w;
-}
-
 DebugWorldState::DebugWorldState(Display& a_Display) : DisplayState(a_Display) {
 	// server
-	game::WorldPtr serverWorld = GetWorld();
 	auto serverFakeSocket = std::make_shared<server::FakeSocket>();
 	m_Server = std::make_unique<server::Server>(serverFakeSocket);
 
 	// client
-	game::WorldPtr clientWorld = GetWorld();
 	auto clientFakeSocket = client::FakeSocket::Connect(serverFakeSocket);
 	m_Client = std::make_unique<client::Client>(clientFakeSocket, "Player0");
 
-	// client2
-	auto clientFakeSocket2 = client::FakeSocket::Connect(serverFakeSocket);
-	m_Client2 = std::make_unique<client::Client>(clientFakeSocket2, "Player1");
+	// TODO: make it better
+	m_Client->OnStateChange.Connect([this](client::Client::State& a_State) {
+		if (auto gameState = dynamic_cast<client::GameState*>(&a_State)) {
+			// render
+			auto clientWorld = gameState->GetWorld();
+			m_Renderer.AddRenderer<render::WorldRenderer>(m_Camera, clientWorld);
+			m_Renderer.AddRenderer<render::EntityRenderer>(m_Camera, clientWorld);
+			m_Renderer.AddRenderer<render::TowerRenderer>(m_Camera, clientWorld);
+			
+			// update state
+			m_ClientState = gameState;
+		}
+	});
 
-	// render
-	m_Renderer.AddRenderer<render::WorldRenderer>(m_Camera, clientWorld);
-	m_Renderer.AddRenderer<render::EntityRenderer>(m_Camera, clientWorld);
-	m_Renderer.AddRenderer<render::TowerRenderer>(m_Camera, clientWorld);
+	m_Client->ChangeState<client::LoggingState>("Player0");
+	std::cout << "Switched to login!\n";
+
+	// // client2
+	// auto clientFakeSocket2 = client::FakeSocket::Connect(serverFakeSocket);
+	// m_Client2 = std::make_unique<client::Client>(clientFakeSocket2, "Player1");
+	// m_Client2->ChangeState<client::LoggingState>("Player1");
 
 	// camera
 	m_Camera.SetCamPos({77, 7, 13});
 	m_Camera.UpdatePerspective(m_StateMachine.GetAspectRatio());
-
-	// states
-	m_ClientState = m_Client->ChangeState<client::GameState>(clientWorld, STEP_TIME);
-	m_Server->ChangeState<server::GameState>(serverWorld);
 }
 
 void DebugWorldState::Update(float a_Delta) {
 	m_Server->Update(a_Delta);
 	m_Client->Update(a_Delta);
-	// TODO: m_ClientState might be invalid !
-	m_Renderer.Render(m_ClientState->GetCurrentLerp());
+	if (m_ClientState)
+		m_Renderer.Render(m_ClientState->GetCurrentLerp());
 }
 
 void DebugWorldState::OnAspectRatioChange(float a_Ratio) {
diff --git a/src/td/game/World.cpp b/src/td/game/World.cpp
index ba9be9a..cb5a935 100644
--- a/src/td/game/World.cpp
+++ b/src/td/game/World.cpp
@@ -1,6 +1,7 @@
 #include <td/game/World.h>
 
 #include <td/simulation/WorldTicker.h>
+#include <td/protocol/packet/PacketSerialize.h>
 
 namespace td {
 namespace game {
@@ -14,7 +15,7 @@ class ColorTileVisitor : public TileHandler {
 	ColorTileVisitor(const World& a_World) : m_World(a_World), m_Result(nullptr) {}
 
 	virtual void Handle(const EmptyTile& a_Tile) override {}
-	
+
 	virtual void Handle(const TowerTile& a_Tile) override {
 		m_Result = &m_World.GetTowerTileColorPalette()[a_Tile->m_ColorPaletteRef];
 	}
@@ -62,6 +63,16 @@ bool World::LoadMap(const protocol::pdata::WorldHeader& a_WorldHeader) {
 	return true;
 }
 
+protocol::packets::WorldHeaderPacket World::GetPacketHeader() const {
+	return protocol::packets::WorldHeaderPacket(m_TowerPlacePalette, m_WalkablePalette, m_DecorationPalette, m_Background,
+		m_SpawnColorPalette, m_TilePalette, GetRedTeam().GetSpawn(), GetBlueTeam().GetSpawn(), GetRedTeam().GetCastle(),
+		GetBlueTeam().GetCastle());
+}
+
+protocol::packets::WorldDataPacket World::GetPacketData() const {
+	return protocol::packets::WorldDataPacket(m_Chunks);
+}
+
 bool World::LoadMap(const protocol::pdata::WorldData& a_WorldData) {
 	m_Chunks = a_WorldData.m_Chunks;
 	return true;