Tip: Switch palace switches normally disappear if you replay the level. However, if you insert them as direct Map16 and use the hex-edit at $00EEB2 in the ROM map, you can replay the level without a problem.
The animation offsets for the animated lava sprite tiles in Iggy/Larry's room (e.g. if you set all of them to the same value, they would all display the same tile at once).
Strangely, some of them are #$04, despite nothing using that bit.