If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
You're a lone, lost, space fighter pilot. You've just flown into Asteroid Alley, the most asteroid packed district of space! There is no escape! All you can do is blast and dodge the asteroids and collect ammo and fuel to last as long as you can.
Arrow Keys - Move.
Spacebar - Shoot.