Trinity Fusion - A Metroidvania Roguelike

Three characters are on a mission to save the dying multiverse. They each have a parallel “self” that guides them on their journey. The worlds are procedurally generated, set in a sci-fi setting. Each character has their own world to explore.
Trinity Fusion is a 2.5D, Metroidvania-styled action roguelike. There are enemies to be destroyed, upgrades to be had, and new biomes to explore.
Note: Trinity Fusion is currently in early access.
Frontier Hunter: Erza’s Wheel of Fortune - An Excellent Metroidvania

Aside from the corny artwork, Frontier Hunter: Erza’s Wheel of Fortune is a great example of how a Metroidvania should get done right. It combines the 2D side-scrolling of both the Metroid series and the Castlevania series, and incorporates a lot of fighting elements as well. Furthermore, there’s some RPG at play here, as your character’s stats will increase after gaining enough experience from defeating monsters.
Frontier Hunter is the successor to Tower Hunter: Erza’s Trial.
Itorah - Good Ol’ Metroidvania Goodness, with a Few Quirks

Itorah is a metroidvania-style platformer developed by Grimbart Tales and published by Assemble Entertainment. You’re in control of a purple-haired girl who has the same name as the title of the game. She can’t talk, but her axe sure can. If you’ve played Indivisible, this game is a lot like that.
Itorah is the only human being left in the world of Nahucan. Everyone else is an animal or a masked organism.