Pretty cool! I'm going to give my honest thoughts here.
The metroid inspiration is obvious, but you do enough new that it feels like its own thing. I especially like the crouching mechanic and how limited the jump height is. Makes the character and world seem more realistic and makes you think about traversing the world differently that you would in most other platformers in this genre.
The only real issues I had were that I thought the character sprites looked weird, and the boss/escape music wasn't very intense. Other than that the art and sounds are great! Can't wait to see where this project goes.