Very cool game. First of all I liked the difficulty very well. It's not unfair but there is definitely a challenge to overcome :)
At next I have to say you had very cool ideas for the rooms and the different enemy types. Also for the graphics. Everything looked very cool. The soundtrack had a nice vibe.
There is only one thing that I didn't liked and that where the controls on keyboard. It was quite difficult to press X for attacking and D for moving. Got a bit tricky.
The only sad thing is that I haven't got any further than the room with those two electric things (I think it's the room on the second gif). I made it up to the platform but couldn't get pass the barrier because there were no enemies to defeat. So I walked back to the room with the boss like enemy but I was also stuck there. Maybe I missed something.
In the end I can say this is a very cool game with cool enemy and room designs, nice graphics, a nice soundtrack and a well chosen difficulty. Maybe not quite a metroidvania? But as I said I sadly haven't played it through so maybe I missed a lot.
Keep it up!