Three dimensions made navigation more important in video games than it ever was in 2D. In 3D you have to figure out where you're supposed to go before you can think about whether or not you'll be able to shoot everything when you arrive. Inversion teases this immediate sense of first having to read the landscape to figure out where you are in space before shooting at the melty mutants and aliens who want your blood. Inversion creates a play arena using shifting centers of gravity - you never know if you're being shot at from the walls, ceilings, or from on the ground straight ahead. In some of the more imaginative rooms you'll have to keep track of whether your character is standing on the side wall, ceiling, or floor.
You'll play as Davis Russel, a cop whose wife was just killed by a massive army of invading aliens on a planet that may or may not be Earth (I asked, Inversion would neither confirm nor deny). Since cops generally travel in pairs, there's co-op, either online or via split screen.
In Inversion's big multi-planar rooms, you'll jump back and forth between walls and ceilings using small blue conduits that toss you onto a new plane. The level I played took place in a volcanic cavern, and several streams of lava flowing downward served as three-dimensional orientation. It's a simple idea, and one that's been used in other perspective-shifting shooters like Prey and Ratchet & Clank Future: A Crack in Time.
Still, the shifting perspective adds a pleasant sense of variation. It reminded me of classic Mario levels where well-familiar gameplay ideas suddenly flip on their heads, where you have to relearn the basics just because the view has changed. It felt like a basic IQ test standing on a ceiling and trying to match my aim with enemies on the ground below. Grenades can be thrown from one gravity field to the next, another neat wrinkle. Toss one far enough, and it will redirect and fall upward along a wall.
Inversion isn't relying on perspective-shifting alone to hold players interest. Davis has a tool called a Gravlink, which works like a gravity gun that you can switch between two modes. Low-G mode fires small globes of gravity disrupting material that sends enemies and debris floating upward for a few seconds of weightlessness. The effect is temporary, and enemies can still attack while hovering in the air but they become less accurate and aggressive. In High-G mode, you can use the Gravlink to bring down big parts of the environment to the ground, allowing you some control over cover placement in an area.
You can also use the Gravlink to pull smaller parts of the environment toward you, like gasoline canisters and cement chunks. The cement can be used like a shield for a brief period, and gas canisters can be used like giant grenades or moved around the environment to create fire traps. There are also tactical limitations on the Gravlink, as it takes a few seconds to fully recharge after a couple of uses. Players will have to think a little more carefully before spraying the world with gravity disrupting pools.
It sounds like Saber might make smart use of these tactical and sensorial elements in multiplayer. Namco Bandai isn't showing multiplayer yet, but it will support 16 players and include a King of the Hill-style mode where teams race each other to a control point that flips gravity on the other team. If the attacking team kicks the defenders off the control point gravity will switch again, making each change in momentum a literal change in orientation. The Gravlink will also run on ammo in multiplayer rather than constantly recharging, rewarding players who learn how best to use its powers.
Inversion will be out on February 7, 2012 for Xbox 360 and PS3. A PC version is also being planned and is likely to ship some time after the console versions.