I don't have a lot to add to what's already been said, unfortunately. :/
The only thing I would really comment on, is that having the barriers right up to the edges of the track feels 'wrong'. You should allow the player to run off the track slightly - maybe half a track width, before they hit any barrier. Obviously going off the track should slow the player down.
In all fairness, I didn't like Mario Kart either, and Mario Kart-a-likes really aren't my bag.
The only thing I would really comment on, is that having the barriers right up to the edges of the track feels 'wrong'. You should allow the player to run off the track slightly - maybe half a track width, before they hit any barrier. Obviously going off the track should slow the player down.
In all fairness, I didn't like Mario Kart either, and Mario Kart-a-likes really aren't my bag.