Puggsy/YMMV

That One Level: Lunar Jet Pug, a thankfully optional example of Unexpected Gameplay Change. No other level, secret or otherwise approaches its level of sadism. You start in a flying saucer with a laser gun, navigating a tight series of passages. Like a merciless game of Operation, touching the edges means instant death, back to the start. Oh, die when you're holding the gun and you drop it onto the instagibbing floor, rendering you defenseless when you find the meteorite room. Fun! Thank God for the ability to exit levels from the pause screen.