I'm really not sure how to introduce InnerSpace, so I'll just say this: it's an upcoming "exploration-heavy flying game" by indie developer PolyKnight Games, and judging by the trailer released this week, it looks beautiful, brain-twisting, and immersive. See for yourself:
According to PolyKnight, InnerSpace features a spherical game world "surrounded by water, where gravity falls away from the center." Players can fly through both sea and air and clear new paths using the ship's guns and "wing-blades." The goal, in PolyKnight's words, is to "explore the various bubble-worlds, collect relics, and encounter each bubble's unique patron deity, in order to discover more about the universe, its history, and its future."
It's hard to tell how satisfying the game is from the trailer alone. Assuming the mechanics feel right, though, I could see myself playing this thing in a slack-jawed daze for hours on end. Perfect for a rainy Sunday afternoon. (Thanks to Rock, Paper, Shotgun for the link.)