Feels very bold to submit a game about biking around a big empty desert to a metroidvania jam less than a year after Metroid Prime 4 came out :P (which I never actually played tbf, so I can't really speak to how this game compares to the infamous desert section in that game, but it's very funny theming that I can't imagine is a coincidence)
This is a pretty nice concept though, the bike was indeed really fun to drive as promised. I liked the camera zooming out as it accelerated, gave a really nice sense of speed. The initial player did feel really painfully slow compared to the size of the environment, but it sounds like you were aware of that and just didn't have time to refine it better, which is fair.
Bigger issue I had honestly was with the control scheme - needing to press and hold a stick and move it at the same time felt really bad (my thumb's still a little sore from it!). I guess that could always vary depending on the controller, but I used a pretty standard Xbox controller so I can't imagine my experience would be uncommon. Adding control rebinding would let me fix it of course, but I'd rather just have the boost be bound to a different input by default. (ig i could've also used the keyboard controls, but seeing that those used the arrow keys for camera control made it seem pretty clear this was meant for controller first)
I also found the flat, unshaded appearance of the sort of temple area where you get your first ability to be really confusing - it makes it really hard to tell where the floor ended and walls began. There was also a lot of camera clipping awkwardness around the walls in there.
Outside of that area the game was visually fine, if obviously unrefined. Though I did have a kind of funny visual error at the ending where the end screen didn't properly scale to fill the window, so it just faded into the corner while the gameplay kept going on the rest of the screen and I watched the bike just keep driving until it fell off the map x).
Don't really have a lot else to say, it's a prototype that's aware it's a prototype and was decent fun to play around with. Some sounds would be nice I suppose, feel like some engine noises would've really enhanced the feeling of speed while driving the bike.