Rescue on Fractalus!

The game uses fractal technology to create the craggy mountains of an alien planet,[4] where the visilibility was drastically reduced by the dense atmosphere. The player controls a fictional "Valkyrie" space fighter[5] (converted for search and rescue duty) from a first-person view, attempting to land and pick up downed Ethercorps pilots.[6] Some of these mountains hold anti-aircraft guns,[7] which have to be avoided or destroyed. Due to the varied terrain, the direction finder has to be used to locate the pilots, whose visual beacons are often masked by mountain ridges.

At higher levels, the enemy Jaggis begin flying kamikaze saucers. The mission area also moves into day/night boundaries. Night missions are particularly difficult, requiring diligent use of the altimeter to avoid crashing.[8]

Flying consumes fuel. The way to replenish this supply is to rescue downed pilots who bring their remaining fuel supplies on board.

The thick atmosphere is sufficiently acidic that downed pilots' craft are being slowly disintegrated. An exposed pilot's survival time outside his craft is less than a minute, due to his flight suit and helmet literally dissolving. This makes it imperative that the player rescue pilots as quickly and efficiently as possible.

After landing within sufficient "walking" proximity to the pilot, the player shuts down the engine, also turning off the ship's shields.[9] Turning on the engines prematurely would incinerate the exposed pilot and the shields would prevent him from entering the ship.[10] The downed pilot then disembarks his crashed ship, runs down to the Valkyrie's cockpit, and knocks on the crew entry door; the player can then open up and let the pilot in to complete the rescue. Failing to open the door kills the pilot; his knocking on the hatch becomes at first frantic, then slower and more feeble as he perishes in the corrosive environment. Sometimes the pilot found is an Ace Pilot, indicated visually by their purple helmet. These are worth ten times the score awarded for a normal pilot to the player.[11]

As a twist on this relatively straightforward premise, added at the suggestion of George Lucas,[12][13] some of the "pilots in distress" are actually hostile aliens in disguise; this twist was kept out of the game's manual and marketing.[14] After landing near a downed pilot, the player watches him run off-screen, and then has to wait for several tense seconds—if it were human, the familiar, frantic "tap-tap" noise would be heard from the ship's hatch; otherwise, the alien Jaggi would suddenly jump back into view, sans helmet, roaring and trying to smash into the cockpit. Unless the player restores the ship's shields, the windscreen cracks open and the pilot is killed. Likewise, inadvertently letting a Jaggi pilot into the player's ship has disastrous results — it begins to dismantle the ship. In early levels, the Jaggi can be distinguished by their green heads versus the white human helmets. However, in later levels the aliens evidently learn to don the human helmet and become identical in appearance. This, along with an unpredictable pause between the human/alien approach and the tap-tap/alien jump makes for a very tense experience. According to head developer David Fox, this shock moment made Rescue on Fractalus! "the first computer game to really scare people".[12]