There is this one Doom-ish game/wad I still can't find to this day.
It started out in a maze garden with bright marble/sandstone floor tiles and green bushes, the garden had a fountain, a 3D bench and a small key lying around somewhere.
After getting the key you could open a gate leading to a castle, this would trigger a loading screen doubling as exposition in the form of a yellow scroll full of german text in fraktur whose contents I can't really remember, something about an evil wizard perhaps.
After that it drops you in front of the castle drawbridge, past that is a room with a small table, a trapdoor behind the table and one prison cell on each side.
The prison cells contained spooky skeleton gifs that either ran straight towards you without dodging anything or aimlessly roamed around, opening the cell doors and punching the skeletons to death would get you a shortsword/dagger.
Past the trapdoor were a set of stairs leading into a long corridor, at the end of said corridor sat a giant red waist-high 3D cockroach.
Setting a single foot in the corridor would cause the roach to charge towards you at sanic speeds and kill you in one hit, which is as far as I ever got in that game.
The game ran at SVGA resolution and was very smooth as I was playing it on a 1ghz CPU under Win9x, I reckon the roach's invincibility and fast movement speed might have been side effects of the game being intended for older hardware.