What exactly qualifies this as 'metroid vania'? the little bits of walking around wrenching things and picking up a new weapon? You know what metroidvania 'is' right? The process of having to acquire new tools or weapons in order to progress through previously inaccessible areas while having the ability to explore freely.
Now, I'm sure you put some work into this game, but 'walky sections' do not a metroidvania make, otherwise it's just a shoot-em-up with only cookie-cutter enemy types and remarkably miniscule variety of weapons.