Arrow Keys to move. S for shield. Spacebar to fire (when you have weapon).
'P' to pause.
Pick up the amount of gold to get better weapons. From the start you have a crappy shield that only works on certain asteroids. Each asteroid has it's own health level also, one hit is not always enough. Also, the Shield has a cool-down period so it can't be used as much as you'd want.
Your ship (you, the player)
Gold (pick up to get weapons)
Asteroids (enemy, avoid or kill)