This is probably gonna come off as somewhat rude, but just know that I like the game, and these are just a few things that I didn't personally like.
My input:
While, yes, I do believe that levels should be uncapped, making them based on how much you use them would make the juice kinda pointless, so, instead of unlocking the perks through things done in-game, you should instead have the player purchase the perks with juice. Health, health regen, stamina, and stamina regen should also still be purchasable by juice, and they should be the only stats you can increase by drinking juice *shudders in health stat grinding in OSRS*
Swirly-D needs to be a boss battle instead of a cutscene where he kills you, or at least, have him replace the clog if you ever return to the toilet world, with a different outcome if you manage to defeat him, the bat should also be either a friendly NPC, or a boss, he seemed way more important than he ended up being.
Ms. Slitherss, who I've heard is supposed to be the final boss, is a big pushover, she needs to have more health (or at least be smart enough to evade attacks, a few shots from the pineapple gun kills her in under a minute) and deal more damage.
Speaking of the pineapple gun, melee needs a serious overhaul, I happened to get the pineapple from breaking one of the crates in the beginning of the game, and I used it until I was forced to use the plunger to kill the Clog. When fighting the Dream Eater, I switched to the worm gun, because the bigger projectiles helped me make easy work of Dream Eater (which is the only time in the game that the worm gun was a viable weapon, that thing needs a buff).
I'd also like for there to be some sort of reward for feeding the flowers, I was kinda hoping that one of the flowers would turn into a giant, optional flower boss, and I'm gonna say, I was actually somewhat disappointed when I gave one over ten thousand juice, and it didn't turn into a boss.
Keep up the hard work, though, I think Juice Galaxy can go from being a good game to a great game with a few tweaks.