Thank you for the feedback !
I agree on most points, and I'm actively working on improving all of these for a post jam version. Already added controller support, reverse, a jump, and better controls overall which makes most dumb situations where the bike is stuck on the side of or against a wall much easier to recover from without restarting.
I'm still battling with the camera but it's slowly getting there.
I'm wondering if maybe the reason why flipped so much was because of air controls ? If you hold the movement keys in the air it adds pitch/yaw forces. It's helpful to do some tricks or make for a better landing but it's not said anywhere and the forces are low enough it's not super noticeable that's what's causing rotation in the air most of the time.
I will use .zip for future jams ! I didn't expect anyone to not have an archiving software available, lesson learned.