Hell Diver for the MZ-700 is a PCG-required game. I mean, you can play the game without it, but it has no graceful fallback for PCG graphics, so it looks like a big mess without it. Fend off the enemies and prevent them from reaching the heart of your base. How many you have to fend off to be successful is beyond me, this is a wildly hard game for me! I can usually knock off a half dozen or so but eventually they overwhelm me and sneak past my meager defenses.

Once they reach a certain point of the playfield, there's a 50% chance they'll run to the reactor and then you lose a life. I've yet to pass the first level!