Sarasaland Adventure v4.0 (SMBX) - Aurora Acropolis (5-3)
Info: https://rpgmaker.net/games/4216/
This is an icy castle-type level where the walls, floors and ceilings are like glass (sorta). I especially like the outside areas. Anywho, this level requires you to go through several rooms to collect keys to unlock the way to the next room. It's also quite dangerous in certain areas as there's lava present and enemies like boos, thwomps, blarggs & girabokkus all around. Luckily, you can use the keys as weapons to dispose of most of these foes here. You'll need to stay on your toes and be careful and don't miss any of the keys or you won't be able to progess. Also, the second star can be cheesed if you're Raccoon Peach; just break the blocks above it with your tail and you can access it without having to hit the blue ! switch in the upper part of the room - though you do need to watch out for the girabokku that's hanging around there.