Press the first letter of the word above an asteroid to lock your aim on it, then type the remaining letters to fire the laser and destroy it. If several words start with the same letter, the game locks the one closest to your ship. It needs a physical keyboard; press Enter on the title screen to start.

A wrong letter just plays an error sound and flashes that asteroid red, so you lose no life and your combo continues. Backspace steps back one letter, and once you are locked on a word you stay on it until it is destroyed or it reaches your ship.

You gain a level for every five words destroyed, up to level 15. Levels 1 to 2 use short three and four letter words, medium words join from level 3 and longer technical words from level 6, and by level 9 the short ones drop out entirely. Asteroids also spawn more often and fall faster at each level.

You start with five lives; every asteroid that reaches your ship costs one and resets your combo to zero. When they run out, the Mission Failed screen lists your score, level reached, WPM, accuracy, max combo, words destroyed and time played, and Enter starts a new run. Esc pauses mid-game and the speaker button in the top corner mutes the sound effects.