The characters and the final boss look very cool, did you make them yourself? The minimal environments have some charm but otherwise the game seems very unfinished and buggy, and not really much of a Metroidvania. A few of the doors led into the void outside the map, and I couldn't figure out how to get up to the ledge with the keycard door. I also couldn't find a way to free the prisoner, but I managed to clip into his cage by attacking and I think I accidentally killed him?
On the other hand, both the final boss and the player seemed unable to kill each other even after depleting their respective health bar to zero, so I kinda just stood there and mashed for a while. I'm not sure if the intended way was to dash in and out between the boss's attacks, but she attacked way too quickly and had way too much health for that kind of hit-and-run tactic to be very viable, especially without any kind of parry or block ability (that I was able to find). Also, attacking the boss while standing too close to the edge of the arena resulted in the player clipping through the wall and getting stuck outside the map.
Overall, the game definitely needs a lot of work! I think I'd focus on improving the feeling of combat first, for example adding sounds and particle effects to the swings and hits, and maybe a block or parry mechanic or some other way to interrupt the boss's attacks.