Shadow Complex is often hailed as one of the best Metroidvania style games around. I never got around to playing it, due to the game being based on the works of Orson Scott Card, but the newest Humble Bundle makes it tough to say no. $1 for Shadow Complex Remastered with a Steam and DRM free key is nice.
Another highlight of this latest bundle is The Vanishing of Ethan Carter, though that is included with the "Beat the Average" tier. I never played that either, but I've always been interested. Everything else I can do without, but the deal is still pretty solid.
via destructoid https://www.destructoid.com/grab-shadow-complex-for-1-in-the-latest-humble-bundle-398469.phtml