This review contains spoilers for the game.
I do like the idea and especially the atmosphere, but the game is incredibly frustrating.
For those wondering how you are even supposed to beat the game: there are hidden areas behind walls that give you additional health potions, if you do not collect those, you will die at the first mini-boss, the same way as @Grimbag.
It took me 6 attempts to beat the final boss, just to get sent to some kind of void in which I couldn't move. After a minute of trying to figure out what to do, I accidentally killed myself (idk how I pressed all buttons).
The combat also lacks any kind of depth. Attacking is the only valid option at any given time, as any action has a 1:1 relation to a counteraction from the enemy. So defending or confusing the enemy essentially just stalls the fight. I though that enemies might have so pattern that I'd have to learn, but I couldn't figure out any, it seems to be completely random. Potion-chugging is the way to go.
With the negatives out of the way, I have to say, that overall, I enjoyed it. Finding the secrets, persevering, and trying new tactics, was fun, if a bit clunky ;) With a bit of polish this could be great.
I would've really loved to know what's at the end though. If anyone beat it, let me know.