Having 100% completed the game, I can say that it's not that great. Unfortunately due to Steam's binary review system, I can only recommend it, or not recommend it, and so I'm going with the latter.
First off, the unlock system was poorly designed. It has both progressive gameplay features, such as turrets and other items, and also cosmetic items such as backgrounds and costumes. You are given tokens to unlock the gameplay items/features, but they're pretty pointless because you have to unlock all of the features/items in its tier (maximum of three) before unlocking the next set of items. It's like skill trees from RPGs, only there's just one of them, and you don't have a choice. The cosmetic items on the other hand, are a nice touch but they're randomized so you can't actually choose them.
The gameplay is interesting, and is definitely different, however it just feels really poorly thought out and broken. The difficulty is just a side effect of the poorly designed concept; it's stuck in this limbo of tower defense and platformer but doesn't do either very well. This is especially apparent in the later levels, when it just becomes a big spamfest of items and the platforming and tower defense elements are all but gone.
I only really wanted to outline the bad things about the game, there are definitely positives to it but I just feel the negatives outweigh them too much.