Ran into an odd bug today. On level 2 I saved my game then walked not too far and opened a Monster Zoo. I kinda screwed up the positioning so I died. When I reloaded the old save, it showed the Monster Zoo room and monsters already revealed. Obviously I was expecting the zoo but it shouldn't show up in an older save as visible.
On a related note, I noticed once that if you open one monster zoo and there's a second, completely separate monster zoo elsewhere on the level, it will also be revealed on the map at the same time. There's probably something a little screwy with the code that reveals stuff on the map for you.
