It may not be a metroidvania in the traditional sense, but has the elements of a 3D metroidvania since you have a large area to explore, get new gadgets as you progress, can backtrack, and has areas that require having the right gadget. It's kind of like the newest Tomb Raider games and God of War 4.
Topic on User talk:Zeephare
Batman Asylum is a metroidvania
Ok buddy. I added Metroidvania Games category.
Oh, okay, I get it, now.