Pilot the spaceship The Silver Future on a journey nine billion miles from Earth to defend the colony Prospero 13 from imminent destruction at the hands of an alien menace. Wave after wave of enemies descend on you, requiring fast reflexes to dodge bullets and collect vital power-ups.
P - Pauses gameplay.
M - Mutes music.
Arrow keys - Control your ship's movement.
Space bar - Fires your ship's weapon.
Collect weapon upgrades by destroying space balloon animals and collecting the icon they drop.
Enemy ships flash briefly before they fire.
Each stage has a pattern. Ships always come out from the same corners at the same point in each stage. If you're having trouble with a particular section, just remember where they enemies pop out from and try to lay down suppressing fire (is it suppressing or sustaining? Hm.) fire in that location before they emerge.