TL;DR: Amazing metroidvania-like platformer with a few downsides

Pros:
-Amazing artwork
-Fitting music
-Constant challenges to keep you on your toes
-Fun boss fights
-Challenging enemies. You can't just mash the attack button, you have to constantly decide how you want to approach a group of enemies, or if you even want to fight them at all
-The upgrade tree and perks are well designed and offer slightly different playstyles

Cons:
-There's no "map tutorial". I didn't know where to go in my first couple of hours. There should be a short tutorial explaining that in each region the ability shrines are priority number one, since they unlock all areas in the region. Also it should be mentioned that the "small rooms" are randomly generated and that your interest lies in the big squares which signal a nearby area
-There's no fast travel. I don't need a way to fast travel to each single region, but when I have to run through 5+ regions to get somewhere while fighting off 2+ hordes, or when I have to spend 3 minutes to get back to a boss arena to fight that boss again, it gets annoying. Maybe allowing fast travel to unlocked shortcuts is a balanced solution?
-Coin magnet shouldn't be a perk but instead default. I can't see how, from a game design perspective, making it non-default enahnces the game experience. There's no challenge to it whatsoever, it's just a constant annoyance