I've got to the second region and have more feedback:
I've completed first region using only arrows, so second one caused a huge difficulty spike - first of all maybe I'm bad but I find using arrows impossible, DFJK is much better in that regard. Secondly, because finding all four keys without muscle memory is quite hard, perhaps 3 sec countdown before level start would be handy.
Also, bike upgrades feel completely underwelming. I know they make sense from realism perspective, but maybe make them visual upgrades down the development, so while being almost useless players at least can see their bike transfrom from half-broken rust bucket to a sleek racing monster.