I used to very intensively play rhythm games, mainly osu!mania and Stepmania (and also later a fork of it, which I will not name due to its incredibly toxic community) and created a bunch of stepcharts for it. Originally intended for Stepmania, I have ported almost all of my charts over to osu!mania now. Check out my osu! profile by clicking here. From there, if you check the Pending or Graveyarded beatmaps, you can find plenty of beatmap packs and single beatmaps.
I currently do not have plans of rehosting my Stepmania packs myself, as they are rehosted elsewhere by other people.
tgmguide is focused on introducing new people into getting started with playing Tetris the Grand Master, an unique spin on Tetris which is mostly single player and extremely focused on self-improvement and breaking your own boundaries to become a Grand Master (Which I have done so myself in the first of the 3 games, so far). It was made using the Jekyll static site generator.
sinewave slicer is my old username but also the alias I used when creating music. I've since laid it to rest, but I figured it wouldn't hurt to leave the music out there. Everything has been written on a Game Boy using a homebrew named Little Sound DJ (or LSDJ), so I had to make my music with the constraints of a real Game Boy - more or less. Sometimes I took a bit of artistic liberty and touched things up using Audacity.
You can find the sinewave slicer Soundcloud account right here.