Crypto - Vania by LUKE LCS

It's a Gaster Megalovania.
Aside from the Gaster theme and general Megalovania-like structure, the song is original.

I used a combination of the EarthBound and Super Metroid sound fonts, as well as some SGM and a built in drum kit from FLEX (which comes with FL Studio)

If you wanna use the song, just make sure to credit me by linking back to either the Sound Cloud or YouTube video.
Please don't simply re-upload the song by itself, or claim it as your own.
If you are using it, please ensure you aren't making money from it.
You are free to use it in any transformative work. These include mashups, remixes, animations, games, videos, ect.

If you do use it in something, be sure to let me know, I'd love to see what you've done with it :D