I enjoyed this game. It felt very SNES with a few modern QoL improvements, which is exactly what I want in a retro 2D game like this. I would recommend it despite feeling like I probably have more nit-picky things to say about the game than good things - but that's okay, because the nit-picky feedback leans more into annoying things that I hope the developer fixes in a sequel (as opposed to anything that full-stop makes me not want to recommend the game). As a 'full package' of art, movement, design, etc. this game delivers.
For me, the level design was the highlight of the game. The levels were diverse, beautifully illustrated, filled with interesting puzzles, and enemy placement (and abilities) felt very on-point.
The character movement (sliding, running, etc.) feels nice and crisp. Once you equip a couple of key upgrades (double jump, wall-hang, etc.) you'll feel very powerful.
The boss fights were a mixed bag. I say this, in part, because it sometimes felt like there was less focus on each boss requiring a unique strategy or ability set and more focus on simply waiting for the right openings to spam your power move (which is in almost all cases OP compared to standard combat).
There are several available power moves for your character, but I honestly only felt like maybe two or three of them were worth equipping. This game very much lacks that feeling you get from games like Megaman X, where every move/power is carefully crafted in such a way that you know you'll need it (sooner or later) to solve a specific puzzle or easily defeat a specific boss. The first move I equipped (an extra powerful punch) mowed down most of the bosses. Perhaps more of the moves are more important for NG+?
The grappling hook mechanic, as many other reviewers have already stated, felt poorly implemented. There are several swinging segments where you're likely to fall to your death multiple times simply because the grapple shoots in the wrong direction or disengages because it brushed against the corner of a random block protruding from the ceiling. I also felt that using the grapple for combat felt like a chore. There is a mechanic that allows you to throw certain items (including downed enemies) and more times than not, in the heat of combat, I threw objects in random directions rather than feeling like I had a lot of control or precision. That could be a me problem, but when the game doesn't necessarily incentive you to learn the the grapple combat mechanics, why bother?
Ultimately, I'd say give this one a try - especially for $10 - $15 if it's on sale.