I got this game from a free key and am glad. I would not have been happy paying for this.
The game isn't incompetently terrible or anything, but it lacks focus and originality. The only really original thing in the game is the rope which has some pretty interesting uses, but I would have been really happy if they had built a game around that mechanic and explored it deeply.
Every aspect of this game feels thrown together fairly without thinking about the other parts. There are a variety of level mechanics that are in the game, but they don't seem to tie to anything beyond what the designers wanted to make that level about. The visual design is not bad but basically is just a pasted-on theme on the same kind of levels. Level progression is weird and unclear - finishing levels unlocks other levels, but there's no real clarity on which levels will be unlocked next, nor is there a sense of progression necessarily. One level might be extremely hard, but it might unlock a very easy level. Some levels are challenging only because they are incredibly long and, since one hit kills, you have to redo the entire level when you die, which can be tedious. (there are maybe three or four levels I can think of that stand out as poorly designed this way)
The music and sound effects: again, just functional, but for some reason there is a sound when your character lands (I finally figured out what that noise was!), the gem-collecting sound is exactly the same every time, no modulation at all, and the music is mostly in tune with the game, but one particularly goofy-sounding song (the main theme in fact) just did not seem to fit at all. I would not be at all surprised if the songs were just public-domain tunes that they used because they were free. (still nothing WRONG with that, just a more effective use would be nice).
The controls are kind of floaty too. I mean, I think that's intentional because you have a cape and that's kind of floaty (also this is a mechanic later, surprise surprise) but sometimes momentum seems off, and lets not even start on the different sized characters.
One last note - if you don't do the levels in the order they want you to, you might show up in a level with a mechanic you're not yet familiar with and have to figure it out yourself. Not too bad really, but poor design nonetheless.
I mean, there's nothing that really makes this game exceptionally bad, but nothing that makes it very good either, and in fact I feel like it turns out to be less than the sum of its parts, simply because it is put together in such a way as to feel disconnected and just bland.
I don't really know why I finished all the levels. I guess getting it for free makes me feel some kind of obligation or something. Whatever. I would say that if you have to pay money for it, pass.