Also, most of the upgrades you can earn while painting a picture are never used. I never got to a point where I could use all those tick and boost upgrades (and the other ones are useless anyway). Maybe add a perk to the shop that lets you get more skill points, maybe even start each picture with some?
I'd recommend going for an incremental style with your upgrades - the way it is now, the game doesn't really change over time because upgrades aren't powerful enough. I got a few upgrades now, which are btw way too expensive and you can get like 1 upgrade per 1-2 pictures, and it doesn't really feel like I'm getting faster at painting - that's not really incremental. Hint: Multiplication instead of addition.
Also, I don't really get the point of some painting costing more inspiration when they sell for the same amount of money?
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