Excellent platformer featuring one of the enemies from Ghosts and Goblins as the main character. This has probably one of the darker themes for Capcom back in its SNES period of releases, with designs of demonic creatures and undead entities that you'd more associate with Konami and the Castlevania series.
An interesting difference to the "platforming" is that technically there isn't any platforming, as your character can fly to a certain extent. When you "jump" up into the air you can choose to keep hovering, but remain locked into that position as you move around. In a ways this makes it kind of like a side-scrolling shoot-em-up, but...uh....also not, since you still can't fly freely about the screen.
You have this ability as soon as the game starts, and it begins with you being attacked by the rotting carcass of a giant undead dragon. As it spits fireballs at you, or breathes flames along the ground, you don't use platforms to avoid these attacks, but instead fly, or drop down, to avoid them.
As you explore the non-linear environments you find new forms, and these allow you to smash certain obstacles, or breathe underwater, or fly in a freer fashion. So you have the action of something like Ghosts and Goblins, but also another layer of mechanics that adds to the exploration elements, or strategies in combat.
Some forms do more damage, some have special attacks or abilities. Some battles you have to keep switching between forms, or environmental obstacles will require different skills. It's one of my favourite Capcom games of all time, and of that SNES era.
I'd say the only downside is that it isn't the most challenging game, with a difficulty level that isn't especially hard, but overall it's a very pleasant and involving mash-up of genres in the action platformer space.
Released as is on pc, it's an instant purchase for me at £10 or so. If they did a remaster that significantly brought this up-to modern standards, I'd quite happily pay £30 for it.