The game is frustratingly under-thought-out in its current state. 90% of the upgrades make no sense; with the exception of the tubes and the passive flow reduction, they're all single-use and couldn't possibly be worth the money that they cost. They at best will help you finish a level where the reward difference is probably a few hundred more, whereas all the non-passive upgrades (most of them) cost anywhere from 1500 to 8000. Also, in order to unlock all the backgrounds you'd need to complete through level 44, but that means you'd need to successfully complete 24 levels in a row with the same character/animation combo, because there's no way to start from a level higher than 20 after selecting those things. Bummed I bought it on steam in this state but didn't want to negatively review there because I'd hope the dev could improve some of this.