If you ever played Modnation Racers on PS3 this is like that but infinitely better in every way. It's Mario Kart, Crash Racing, and Modnation Racers combined. No microtransactions, 6 player offline splitscreen, online multiplayer, mod support, track builder, etc. Been waiting for this for a long time, by far the best kart racer ever released on PC. It's in early access on steam today.
https://youtu.be/gD6r2lltY1U