I think the aiming system is pretty nice, it being limited to 8 angles and not being able to aim down would let you design some pretty interesting challenges, like needing to jump to hit some enemies that are on an awkward angle for your gun but also having to be on the ground to hit incoming ground enemies, besides that I think you could easily make the game look very nice with a couple of textures for the platforms and a simple background, would love to see a more refined version of this after the jam ends :)