The first jump is a bit difficult, and since the player has experienced way longer airtime on the stomper before, the toned-down bounce either feels like the player is doing something wrong or the physics bugged out. Maybe think about implementing the boost function into the basic control scheme of "a" and "d" inputs to make the experience a bit more streamlined. The game feels unique and has a lot of potential for interesting level design. Great idea, really good execution, well done!