> getting stuck in the walls
I remember the early Simpsons video game. Sometimes, due to some bug in it (probably a sign error), you could go through the walls and see the rendered scenery from the other side. It was like you went backstage in a play. It would have made a great Twilight Zone episode!
Those bugs I experienced in all sorts of games and via cheats, fly mode, I intentionally went backstage to explore.