Intresting, a metroidvania!
Often a dev make a metroidvania and submit it for a jam.
I played a lot of this games but are all broken or very incomplete.
This is different.
Yes it's small(obvious, it's a jam game) and the power ups it's not super original but it works really well. Has a good progression and even a "AH-AH!" moment if you explore well (no spoilers ;) ) reminds me a lot of Ghost and Goblins (yeah, i know, not a metroidvania) in the jumping and even the enemies. I played about 40/60 mins beacause i had fun e wanto to explore all of it.
Couple of issues:
Like you said: controls for keyboard it's uncofortable. I'm a "seasoned" metroidvania/platform player forged by the flame of thousands jumps and tricks so, with a little bit of effort i could still playing it. People not in the genre...i don't know with these controls.
In the Casrtle Garden there is a small platform that protect you to go in the purple water but i pressed S and I ended up there anyway. So i tried to go right and left and i could pass under the walls. I tought I found a secret but...nope. Then i died when i got close to the spikes.
The S button for jumping off platforms sometimes works and sometimes the character get stuck in the middle of the pixels
In the Center Yard if you try to explore with the bat form you can jump completley the first boss and go directly to the shadow lord room. If you go further you can go out of bounds and fall infinitley.
But despite that (not big issues in my opinion for a jam game) , it's a great work!