For people wanting to buy this:
What you see is what you get. Watch the trailer and you should have a basic idea of what you're buying. Game is about 30-60 minutes to beat depending on how good you are at platformers.
For the dev:
Overall I would say positive. What you see is what you get so while the animations weren't my cup of tea you did deliver exactly what I expected you to. Art is fine, animations look great, and the enemy designs are clever.
The gameplay itself is the weakest part. Lots of blind jumps everywhere, no run button, and really heavy gravity make for a poor platforming experience. When you don't know if you can make 1 tile wide jumps, that's the sign that you may need to re-test your jumping physics. The fact that the jump key opens doors as well is pretty annoying, especially since you have to wait for the open animation to play out, and especially when W could have opened doors just fine. The enemies were varied which was nice but their difficulty ranged from "barely noticeable" to "ninja gaiden levels of bs". Especially when they knock you into spikes that are an instakill, and dying resets all the keys you've gathered.
The boss was nice, no complaints there. It's easy to cheese and the poor jumping makes using cheese the only viable way to beat her, but overall the boss was fine.
If you decide to make another platformer, don't copy and paste the player code and instead rework it so jumping feels better. Adding coyote time will help too trust me. Also more checkpoints. I really see no reason why collecting a key/potion doesn't give you a checkpoint, since you typically get the key after beating a challenge. It's up to you but the amount of unfair deaths made the game feel bad when I had to restart all of my progress.