ice castle was always my favourite area.
i love the aesthetic and the music. the synthesised marimba sounds surprisingly good with game maker 7's reverb and chorus effects.
it's not a hard area but it's great fun with lots of heart gates and secrets.
the boss is cool, i just wish it was a little more challenging. i remember watching raocow's playthrough when he thought it might start a second phase. that would've been fun. i mean, it's a super lategame area, you have to get through the curtain to get there anyway, so you usually have 800+ health.
that reminds me. in an unofficial story there was this area called magmacavern, it had amazing music. probably one of the best midis i've ever heard. ironic because that area was short and didn't even have a boss. is that an original midi or was it from another game? i actually decompiled it to try and find what it was from, but the file was named something non-descriptive so that didn't help. though i found the music for the snow area (it was blade mountain from pac man world 2) so it wasn't a complete waste of time.
i hope i didn't ramble too much.