Thanks for the responses guys.
For now however, I'm led to believe that people like me who are waiting for a mario-kart styled game just have to keep waiting. The main thing I can't believe I forgot to say at the start was that ONLINE multiplayer was a compulsory addition.
Call me picky, but none of those games satisfy me. Tiki kart is indeed quite fun to play, but the multiplayer is too patchy for me; no form of username or friend system, you just automatically pair up with anyone around the world regardless of ping? Ridiculous.
Shrek Kart on the other hand I haven't even bothered installing for two reasons: the fact that it's not on play store means that it's definitely not well known and therefore multiplayer would be a hard experience to enjoy. However, the fact that it only has local multiplayer is an incredible turn off for me too.