Very interesting, although I think the ammo recovery should be time based rather than distance traveled. And if you had distance traveled because the player is finding bullets, what if it's an energy weapon with a recharging battery? Or an ammo printer? Maybe even a pressurized air gun with a tank of gas?
The player doesn't seem to fast or to slow, and the gun control is very basic, but usable.
Overall, I think it's a pretty good game design, I think the using bullets to jump makes for some interesting resource management.
BTW I found the link from the GDquest discord, if you are wondering.