Zero G Arena is an online multiplayer, 3rd person arena shooter, with zero gravity. Players have magnetic shoes that can be turned on or off to switch between running on magnetic surfaces and floating. Players also have a grapple beam, which can be used for swinging or pulling towards objects or surfaces, as well as a wall jump, which can be used to kick off from surfaces while floating.
The mechanics can be used in combination for a practically unlimited range of manoeuvres. The zero gravity mechanic is supported by ragdoll physics, so that the in-game avatars react convincingly to forces and the environment.
The aforementioned magnetic surfaces can be at different angles to each other, allowing for interesting situations such as where your wall is another player's floor.
Please note the game is in Early Access, and it really is pretty early in development. Also, right now, I cannot guarantee I'll decide to finish the game but it will not become paid before I have decided. See the Early Access section above for more information. For now, it's free, so you don't stand to lose a lot by trying it out, just don't expect anything like a finished game.
I'm not expecting or aiming for large numbers of players in the early stages of Early Access, so for now, you'll probably have to organise games in advance, either with friends or in the community hub. If you're not willing to do that, you might want to wait until the full release before playing the game.