     @engine.start()
 
   update: (dt) =>
-    if @hadGameOver
+    if @had_game_over
       if @engine.buttonJustPressed(Button.Key_Space)
         location.href = location.href
       return
     score_per_sec = 60
     @score += score_per_sec * dt
 
-    @nextMeteor -= dt
-    if @nextMeteor <= 0
-      @nextMeteor = @nextMeteorInterval
+    @next_meteor_at -= dt
+    if @next_meteor_at <= 0
+      @next_meteor_at = @meteor_interval
       @createMeteor()
 
-    @nextMeteorInterval -= dt * 0.01
+    @meteor_interval -= dt * 0.01
 
     for obj_list in [@stars, @meteors]
       for obj in obj_list

    context.fillStyle = "#ffffff"
    context.font = "30px Arial"
    context.fillText "Score: #{Math.floor(@score)}", 0, 30
    if @hadGameOver
      context.fillText "GAME OVER", @engine.size.x / 2, @engine.size.y / 2
      context.font = "18px Arial"
      context.fillText "space to restart", \

      pos: new Vec2d(0, @engine.size.y / 2)
    @ship_vel = new Vec2d()

    @meteor_interval = 0.3
    @next_meteor_at = @meteor_interval

    @score = 0

