I had Doom 1, 2, 3 and the toolkit. There was this huge level that left right from the cortyard of level 1. It was so big you couldn't save the game. You just had to get tired and quit. There was a deathstar level with stormtroopers. There was another called osiris that was basically the mummy meets stargate. There were hundreds of regular doom levels. There was even a way to turn the monsters into Barney the dinosaur or presidential characatures.

I could name dozens of other games, Ken's labyrinth, Monster Bash, Crush Crumble and Chomp, Blake Stone. The original castle wolfenstein was a 2d game on Commodore 64. The list goes on. None of them work now.