Interesting concept, good control, good artwork. The progression is decent but I think it would feel nicer if there were some occasional money bonuses. The predictability of doing the math in your head like "okay, I want that upgrade so I have to do exactly 4 more runs of this build..." instantly puts you in a calculated grind mindset, so tossing out an occasional moneybag pickup to shoot, or a multiplier for not taking any damage in the level, or things like that could alleviate that feeling.
LOWREZJAM 2020 » Entries » Cundle, or, Over the land and not that other thing that this title may or may not remind you of