Megalovania Remake*: I tried to keep this a solid mix between soundfonts and traditional GarageBand instruments, and I think it turned out well. The end has some extra track-soloing bits. I used
Megalovania for Percussion Ensemble Sheet music for Vibraphone, Glockenspiel, Snare drum, Marimba & more instruments (Percussion Ensemble) | Musescore.com
Megalovania (Undertale) Sheet music for Bass voice, Bass guitar, Drum group, Strings group & more instruments (Mixed Ensemble) | Musescore.com
Stream episode Megalovania with Arsenal Instruments by Campyfire podcast | Listen online for free on SoundCloud
The Undertale Sample/Soundfont/VST/etc. list! (WIP) : r/Underminers