It is… kind of. Hence the half-cheat. First off it’s 3D, but the game is completely centered around the Oldest House, which is the headquarters of the fictional FBC. Like a Metroidvania you explore and backtrack back and forth through it and unlock new areas opening up from previous places. There is also one (although only one) proper ability gate that lets you explore previously unreachable parts of earlier areas once unlocked.

Even if you don’t classify it as a true Metroidvania it’s definitely Metroidvania-inspired.