A bit of animation for when you take damage or something like that would be nice, so it doesn't feel as abrupt when you die. Also, I presume there's some sort of logic behind how often you encounter upgrades, so some sort of "map" that tells you when the next upgrade is coming up. Also a shop would be a priority, maybe it would sell consumables for cheap as well as more expensive permanent, with some sort of limited backpack space mechanic? Either way, this is pretty cool so far.