diff --git a/index.html b/index.html
index 7b3d118..fb5aed8 100644
--- a/index.html
+++ b/index.html
@@ -84,8 +84,13 @@
             last = timestamp(),
             step = 1 / 60;
 
-        var position_x = 100;
-        var position_y = 100;
+        const GameState = {
+            PLAYING: 0,
+            STARTSCREEN: 1
+        };
+
+        var current_gamestate = GameState.STARTSCREEN;
+
 
         function frame() {
             now = timestamp();
@@ -130,11 +135,20 @@
 
         // Fixed time loop
         function update(dt) {
-            player.position_y += player.velocity_y * dt;
-            player.position_x += 100 * dt;
+            if (current_gamestate == GameState.PLAYING) {
+                player.position_y += player.velocity_y * dt;
+                player.position_x += 100 * dt;
 
-            // Gravity
-            player.velocity_y += GRAVITY * dt;
+                // Gravity
+                player.velocity_y += GRAVITY * dt;
+
+                // Lose condition
+                if (player.position_y > 400) {
+                    die();
+                }
+            } else if (current_gamestate == GameState.STARTSCREEN) {
+                // Do nothing
+            }
         }
 
         // Variable time render loop
@@ -145,13 +159,33 @@
             });
         }
 
-        // Jump
+
+        function die() {
+            current_gamestate = GameState.STARTSCREEN;
+        }
+
+        function restart() {
+            player.position_x = 100;
+            player.position_y = 100;
+
+            player.velocity_y = 0;
+
+            current_gamestate = GameState.PLAYING;
+        }
+
         document.onmousedown = function (evt) {
-            player.velocity_y = -JUMP_VEL;
+            if (current_gamestate == GameState.PLAYING) {
+                // Jump
+                player.velocity_y = -JUMP_VEL;
+            } else if (current_gamestate == GameState.STARTSCREEN) {
+                restart();
+            }
         };
 
         requestAnimationFrame(frame);
     </script>
+
+
     <div id="viewport">
         <div id="floor" style="
         left:0px;