Ope, I didn't see Nightmare Kart but I guess I didn't scroll far enough. I figured Dusk and Fatum Betula were probably on your radar, but just in case. :)

A few more recommendations!

https://store.steampowered.com/app/519860/DUSK/

https://store.steampowered.com/app/1281270/Fatum_Betula/

https://store.steampowered.com/app/2930160/Nightmare_Kart/

And pretty much all of the Dread X Collections:

https://store.steampowered.com/publisher/DreadXP/list/81606

Check out this THPS-inspired unicycle game! Haven't played it yet, but looks great and I've heard positive things.
https://store.steampowered.com/app/2204900/STREET_UNI_X/