I'm old, so I'm serious.
I've played mariokart64, CTR, etc..
I've seen STK when it has no textures.. I can say I play it from the beginning.
And seriously, it's a great peace of free software. Nice job every one!
Now, I think so details should be improved.
Biggest one: bananas.
I think the approach is totally wrong with this game concept.
I suggest to change bananas to some thing that looks like penalties. That could be many things: a ugly box, a package, a classic game penalty symbol (skull, etc..).
(what is the word for the opposite of bonus in english? malus?)
And bananas should be.. bananas. What happen when you drive on banana peel? You slip!
So I suggest a random effect, chosen from: slip left, slip right, slip forward for 10meters, change physique for 3seconds, the peel sticks against the glass of the player's screen, and then slides slowly leaving traces for the whole race.
Many thing but NOT having a bomb, an anchor and all that: that is for penalties!
AND with the new concept of penalty box, we can also imagine a random box: it has only best bonus and strongest penalties, so you really take a risk when you choose one!
I can add I think this from my long experience, I wish my thinkings will add something to this amazing project!
Best!