My dude, I love the 2.5 mixed with 3D kart race! It's actually pretty charming art style wise. The music is catchy and fitting for a kart race.
I think the idea definitely can be expanded upon. As for now I don't really see much difference on what hover mode provides even though it's mentioned about the tighter spin. If the game is going to get expanded, I would love to see more of the hover/wheel bigger implementation like jump then hover fly part of the map for example; to make the switch implementation more of a highlight and a mandatory for player to use even though they're losing the race.
Great work! Also good job on the characters, I love how every single one drawn. Everyone represented have so much personality and in the tracks too!