diff --git a/server/HELP.md b/server/HELP.md
deleted file mode 100644
index 26935c7..0000000
--- a/server/HELP.md
+++ /dev/null
@@ -1,21 +0,0 @@
-# Getting Started
-
-### Reference Documentation
-For further reference, please consider the following sections:
-
-* [Official Apache Maven documentation](https://maven.apache.org/guides/index.html)
-* [Spring Boot Maven Plugin Reference Guide](https://docs.spring.io/spring-boot/docs/2.3.1.RELEASE/maven-plugin/reference/html/)
-* [Create an OCI image](https://docs.spring.io/spring-boot/docs/2.3.1.RELEASE/maven-plugin/reference/html/#build-image)
-* [Spring Web](https://docs.spring.io/spring-boot/docs/2.3.1.RELEASE/reference/htmlsingle/#boot-features-developing-web-applications)
-* [Spring Data JDBC](https://docs.spring.io/spring-data/jdbc/docs/current/reference/html/)
-* [Spring Data JPA](https://docs.spring.io/spring-boot/docs/2.3.1.RELEASE/reference/htmlsingle/#boot-features-jpa-and-spring-data)
-
-### Guides
-The following guides illustrate how to use some features concretely:
-
-* [Building a RESTful Web Service](https://spring.io/guides/gs/rest-service/)
-* [Serving Web Content with Spring MVC](https://spring.io/guides/gs/serving-web-content/)
-* [Building REST services with Spring](https://spring.io/guides/tutorials/bookmarks/)
-* [Using Spring Data JDBC](https://github.com/spring-projects/spring-data-examples/tree/master/jdbc/basics)
-* [Accessing Data with JPA](https://spring.io/guides/gs/accessing-data-jpa/)
-
diff --git a/server/src/main/java/gltronic/tronio/business/GameManager.java b/server/src/main/java/gltronic/tronio/business/GameManager.java
index 9023b6b..6a89faa 100644
--- a/server/src/main/java/gltronic/tronio/business/GameManager.java
+++ b/server/src/main/java/gltronic/tronio/business/GameManager.java
@@ -1,29 +1,130 @@
 package gltronic.tronio.business;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Random;
 
+import org.json.JSONObject;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.socket.WebSocketSession;
 
+import gltronic.tronio.model.Game;
 import gltronic.tronio.model.Player;
+import gltronic.tronio.model.Wall;
 
 public class GameManager implements IGameManager {
+  @Autowired
+  Game game;
 
   @Override
   public void login(WebSocketSession session) throws InterruptedException, IOException {
-    // TODO Auto-generated method stub
+    if (game.getSessions().containsKey(session.getId())) {
+      SocketUtils.sendMessage(session, "error", "cant login twice");
+      return;
+    }
+ 
+    Player player = initPlayer(new Player());
 
+    game.getSessions().put(session.getId(), session);
+    game.getPlayers().put(session.getId(), player);
+
+    SocketUtils.forwardMessage(session, "login", new JSONObject(player));
   }
 
   @Override
   public void leave(WebSocketSession session) throws InterruptedException, IOException {
-    // TODO Auto-generated method stub
-
+    game.getSessions().remove(session.getId());
+    game.getPlayers().remove(session.getId());
   }
 
   @Override
-  public void update(WebSocketSession session, Player player) throws InterruptedException, IOException {
-    // TODO Auto-generated method stub
-
+  public void updatePlayer(WebSocketSession session, Player player) throws InterruptedException, IOException {
+    Player playerToUpdate = game.getPlayers().get(session.getId());
+    playerToUpdate.setAngle(player.getAngle());
+    playerToUpdate.setTargetAngle(player.getTargetAngle());
+  }
+
+  @Override
+  public void step() throws InterruptedException, IOException {
+    // CHECK OUT OF BORDERS & COLISIONS
+    game.getPlayers().forEach((id, player) -> {
+      // OUT OF BORDERS
+      if (player.getX() - game.getSettings().getPlayerSize() < 0 ||
+          player.getX() + game.getSettings().getPlayerSize() > game.getSettings().getArenaSize() ||
+          player.getY() - game.getSettings().getPlayerSize() < 0 ||
+          player.getY() + game.getSettings().getPlayerSize() > game.getSettings().getArenaSize()) {
+        killPlayer(id);
+        return;
+      }
+
+      // COLLISIONS
+      game.getPlayers().forEach((id2, player2) -> {
+        for (var i = 0; i < player2.getWalls().size() - 2; i++) {
+          Wall wallA = player2.getWalls().get(i);
+          Wall wallB = player2.getWalls().get(i + 1);
+          if (isCloseToWall(wallA.getX(), wallA.getY(), wallB.getX(), wallB.getY(), player.getX(), player.getY(), game.getSettings().getPlayerSize())) {
+            if (this.isCrossingLine(wallA.getX(), wallA.getY(), wallB.getX(), wallB.getY(), player.getX(), player.getY(), game.getSettings().getPlayerSize())) {
+              killPlayer(id);
+              return;
+            }
+          }
+        }
+      });
+    });
+
+    // ADD WALLS & MOVE PLAYER
+    game.getPlayers().forEach((id, player) -> {
+      // WALL
+      player.setLastWall(player.getLastWall() + 1);
+      if (player.getLastWall() > game.getSettings().getWallUpdate()) {
+        player.getWalls().add(new Wall(player.getX(), player.getY()));
+        player.setLastWall(0);
+      }
+
+      // MOVE
+      player.setX(player.getX() + game.getSettings().getPlayerSpeed() * Math.cos(player.getAngle()));
+      player.setY(player.getY() + game.getSettings().getPlayerSpeed() * Math.sin(player.getAngle()));
+    });
+  }
+
+  private void killPlayer (String id) {
+    Player player = game.getPlayers().get(id);
+    initPlayer(player);
+    SocketUtils.sendMessage(game.getSessions().get(id), "dead", "yo dead");
+  }
+
+  private boolean isCloseToWall (double xa, double ya, double xb, double yb, double xc, double yc, double radius) {
+    var xar = Math.min(xa, xb) - radius;
+    var yar = Math.min(ya, yb) - radius;
+    var xbr = Math.max(xa, xb) + radius;
+    var ybr = Math.max(ya, yb) + radius;
+
+    return ((xc >= xar && xc <= xbr) && (yc >= yar && yc <= ybr));
+  }
+
+  private boolean isCrossingLine (double xa, double ya, double xb, double yb, double xc, double yc, double radius) {
+    var a = xc - xa;
+    var b = xb - xa;
+    var c = yc - ya;
+    var d = yb - ya;
+    var result = (a * d - b * c) / Math.sqrt(Math.pow(xa - xb, 2) + Math.pow(ya - yb, 2));
+
+    return result < radius;
+  }
+
+  private Player initPlayer(Player player) {
+    Random rand = new Random();
+    double x = game.getSettings().getArenaSize() * (0.25 + Math.random() * 0.5);
+    double y = game.getSettings().getArenaSize() * (0.25 + Math.random() * 0.5);
+
+    player.setAngle(0);
+    player.setTargetAngle(0);
+    player.setLastWall(0);
+    player.setWalls(new ArrayList<Wall>());
+    player.setColor(String.format("#%06x", rand.nextInt(0xffffff + 1)));
+    player.setX(x);
+    player.setY(y);
+
+    return player;
   }
-  
 }
\ No newline at end of file
diff --git a/server/src/main/java/gltronic/tronio/business/IGameManager.java b/server/src/main/java/gltronic/tronio/business/IGameManager.java
index feaeae0..d82fe1f 100644
--- a/server/src/main/java/gltronic/tronio/business/IGameManager.java
+++ b/server/src/main/java/gltronic/tronio/business/IGameManager.java
@@ -9,5 +9,7 @@ import gltronic.tronio.model.Player;
 public interface IGameManager {
   void login(WebSocketSession session) throws InterruptedException, IOException;
   void leave(WebSocketSession session) throws InterruptedException, IOException;
-  void update(WebSocketSession session, Player player) throws InterruptedException, IOException;
+  void updatePlayer(WebSocketSession session, Player player) throws InterruptedException, IOException;
+
+  void step() throws InterruptedException, IOException;
 }
\ No newline at end of file
diff --git a/server/src/main/java/gltronic/tronio/model/Player.java b/server/src/main/java/gltronic/tronio/model/Player.java
index 9728374..7b4150c 100644
--- a/server/src/main/java/gltronic/tronio/model/Player.java
+++ b/server/src/main/java/gltronic/tronio/model/Player.java
@@ -10,7 +10,6 @@ import lombok.Setter;
 @Setter
 @NoArgsConstructor
 public class Player {
-  private String id;
   private double x;
   private double y;
   private double angle;
diff --git a/server/src/main/java/gltronic/tronio/model/Wall.java b/server/src/main/java/gltronic/tronio/model/Wall.java
index adbbea2..e1f3284 100644
--- a/server/src/main/java/gltronic/tronio/model/Wall.java
+++ b/server/src/main/java/gltronic/tronio/model/Wall.java
@@ -1,5 +1,6 @@
 package gltronic.tronio.model;
 
+import lombok.AllArgsConstructor;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.Setter;
@@ -7,6 +8,7 @@ import lombok.Setter;
 @Getter
 @Setter
 @NoArgsConstructor
+@AllArgsConstructor
 public class Wall {
   private double x;
   private double y;
diff --git a/server/src/main/java/gltronic/tronio/web/SocketHandler.java b/server/src/main/java/gltronic/tronio/web/SocketHandler.java
index b45ddab..1cb7b01 100644
--- a/server/src/main/java/gltronic/tronio/web/SocketHandler.java
+++ b/server/src/main/java/gltronic/tronio/web/SocketHandler.java
@@ -30,10 +30,8 @@ public class SocketHandler extends TextWebSocketHandler {
 
     String type = (String) jsonObject.get("type");
     switch (type) {
-      case "alive":
-        break;
       case "update":
-        gameManager.update(session, (Player) jsonObject.get("update"));
+        gameManager.updatePlayer(session, (Player) jsonObject.get("update"));
         break;
       default:
         SocketUtils.sendMessage(session, "error", "unknow command");
diff --git a/server/target/classes/gltronic/tronio/business/GameManager.class b/server/target/classes/gltronic/tronio/business/GameManager.class
index 4fc980f..79d9fb3 100644
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diff --git a/server/target/classes/gltronic/tronio/business/IGameManager.class b/server/target/classes/gltronic/tronio/business/IGameManager.class
index 4c40937..6e31afb 100644
Binary files a/server/target/classes/gltronic/tronio/business/IGameManager.class and b/server/target/classes/gltronic/tronio/business/IGameManager.class differ
diff --git a/server/target/classes/gltronic/tronio/model/Player.class b/server/target/classes/gltronic/tronio/model/Player.class
index 16b2818..a7ccc47 100644
Binary files a/server/target/classes/gltronic/tronio/model/Player.class and b/server/target/classes/gltronic/tronio/model/Player.class differ
diff --git a/server/target/classes/gltronic/tronio/model/Wall.class b/server/target/classes/gltronic/tronio/model/Wall.class
index 62ec354..fb604d1 100644
Binary files a/server/target/classes/gltronic/tronio/model/Wall.class and b/server/target/classes/gltronic/tronio/model/Wall.class differ
diff --git a/server/target/classes/gltronic/tronio/web/SocketHandler.class b/server/target/classes/gltronic/tronio/web/SocketHandler.class
index 00f5997..2ea1408 100644
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