There is no Atari ST cover art on file for this game
Scattered throughout the 18 different fortresses are boxes. Shoot these open to find either a) Fuel: this will replenish your supply, which is drained by shooting and accelerating. b) Sun crystals: Collect all to finish the mission. c) Bombs. They will explode in 30 to 60 seconds, destroying your ship. You can avoid that by leaving the screen quickly, or by picking the bomb up; this earns you major credits, but your ship drops much faster due to increased weight. d) Pearls. Collecting these advance the upgrade counter by one to three steps; you may activate the current upgrade at any time, which will improve your rotation speed, engine strength, weapon, shield etc. Boxes are emptied by carefully flying very, very close to them and activating a tractor field.
As if gravity and accurate flying wasn't challenging enough, the game also confronts you with various enemies. All of these are immobile and fire in a straight line; the sheer mass of them makes avoiding the bullets a difficult task nevertheless. Apart from turrets, there are attractors and repulsors who'll smash you into walls, and force fields that need to be deactivated by finding and shooting a switch.
The tricky labyrinths together with the short supply of fuel, weight constraints and clever upgrade system make Rotor more a game of tactics and accuracy than arcade action. Wild shooting and careless flying will deplete your fuel in no time; you'll have to progress carefully to discern traps in time.