Another weird gravity stage. The gravity isn't low like it was in Star Man's level, but it's REVERSED at portions of the stage! This makes for some very interesting gameplay. It's a rather typical stage apart from the obvious gravity gimmick, with spikes being the biggest threat. Be careful not to land on them!
You'll find the Beat Letter near one of the "gravity change" bars, and you have to time a jump just right to reach it, without falling to your death. Don't despair, it's really not that hard to get to.
Gravity Man himself is as strange as the stage he hides out in. He constantly changes the gravity in the room, firing at you and jumping around as he does so. You'll always be on the opposite surface as him, so you have to fire at him as the two of you cross each other en route to the other floor when he changes the gravity. He's weak to the Star Barrier, but this is the hardest weapon to hit with since it more or less requires you to be at point-blank range. An alternative is to stay as far from him as possible, and just fire your regular weapon. It will take longer, but it is a safer alternative if you don't dare try the Star Barrier method.