This is a nice little Space Invaders / Galaga type game, where you fight against glowing orbs. It starts out pretty simple, but pretty soon they start shooting back. And then they start coming after you. And then they send out their boss. Well, you know the drill. Note: See below game for instructions and tips.
Instructions: Arrow keys move; spacebar shoots. Right mouse button for options. It takes a while before the ships start charging you; early in the game, they basically just sit up there and let you shoot at them. Later on, though, things start getting rather challenging. Powerups occasionally fall your way. Try to conserve them when you get them, and make your shots count if you’ve got a double-photon weapon.