Incredible Mandy is a lovely looking platformer-adventure about the dreams of a brother and sister, who must unlock the memories they hide following a tragic accident. Left without his hand as a result of the trauma, Mandy's brother can manifest the Excalibur of Light in its place, a "symbol of positive power" he wields as he journeys through strange, beautiful dream worlds under the guidance of his sister.
That is an undeniably vague description, and you won't find a whole lot more on Steam. "From mountain peaks to deep canyons, from sea shores to hidden corridors, search for clues and solve innovative puzzles; use the sword in your hand and the wisdom of your mind to challenge overwhelming foes," the list states. "Can you pierce through the mist of dreams and discover the unexpected truth?"
The lack of clarity is made up for to a large extent by the presence of a downloadable demo, so you can grab it and try it risk-and-hassle-free even if you're only a little curious about what's going on. I've played with it a bit—not far enough to get into the underlying themes of loss and recovery, but enough to sample the systems and get eyes on the game world—and it looks very promising.
Do note that progress from the demo will not carry over to the full game: developer Dotoyou said that there are differences in the content and the order it's introduced, so that keeping save games is impossible. The full game will have eight unique chapters, each with a puzzle level and boss fight, and if you're more into exploration than extermination an explorer mode option promises to greatly simplify combat so you can focus on sightseeing.
Incredible Mandy isn't actually live on Steam just yet, but it's slated to happen today.