It's a fun racing type platformer. It's a good idea with plenty of room to expand! I like the idea of needing to get home before nightfall.

The movement feels too slippery though. I think it should either be tighter or the levels should be designed to make the slippery movement have a purpose (feel like drifting when going around curves).

I'm not sure what the diamond things did/do. I'm assuming they're just a collectable which is fine! If that's the case some indication of how many you collected out of how many in the level on a level select screen for example would be nice (3/5 collected).

I noticed a bug involving restoring a player who fell. If you just walk off a ledge, you get stuck into a loop of falling into the pit over and over unable to move. It is really funny to watch though.

Great job!

Cool platformer and original mechanic wih darkness, I like it!