For the most part I liked it! Managed to pack a lot of Metroidvania into a fairly small map.
My only complaint really is that even with such a small map, I often found it hard to figure out where to go - trying to remember where the different pink block areas were to know when I could visit what areas after hitting the switches was a bit much sometimes. I ended up having to go over the entire map again to get the last two stars and monsters because I'd totally forgotten that the entrance to the two cell block was the block above that had simply been blocked by a pink wall the first time I'd been through. And I think I might have gotten to a couple of places early with some tricky jumps that threw me off, not realizing I should have gone another way first (because the other way had been blocked, and then I forgot about it, because there was no hint on the map that there was further to go).
Although with a map so small, maybe easier navigation hints (like Metroid's indicators of whether there's a path between two adjacent cells) might make it too easy, so I'm not sure I have any ideas.
Overall, nicely done though. Probably one of the better Metroidvanias I've played on here.