✓ Fits the Metroidvanias cluster, with adventure storytelling, Metroidvania exploration and precision platforming
≠ Where it differs: brings puzzle design, dark, oppressive atmosphere and melee combat, while skipping setting scifi
Skeletonized rabbit Ash lives in Hell, he's a prince of that place. Ash is busy recovering his hellish reputation - killing everyone in Hell, who saw his photo with a rubber duckling in the bath. Apparently, among the princes of Hell to play with the duckling is not common.
It predates Shadow Labyrinth by 13 years, with what that implies technically.