That was the most gucci I have had in a while. I think you are aware of some areas of expansion: increasing the max level, adding more options in the skill table that does not make the player reliant on rainbow enemies to get large upgrades, the use of legendary upgrades maybe at 5.0 level or such, and actually making skull level three "possible"; The main issue is that I can not become powerful fast enough even with max upgrades to conquer that level; ultimately as a Vampire Survivors-Like, you want the player to progressively feel overpowered, and I like the mechanic of requiring several games to upgrade your stats, but it just needs to be expanded upon, which I expect you will do. Along with the skill tree, maybe allow permanent upgrades (so that in game you may start at 2.0, etc.), or allowing the player to increase regen times, maybe add health regen option, increase mobility, etc.