If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
You can play this game alone or as 2 players. Objective of the game is drawing your line. Don't touch your friend's or own line while playing. If you are Player1; control with "W,A,S,D" keys and turbo with "Tab" key. And Player 2 controls with "Arrow Keys" and uses "Enter" to turbo.