ZeroG is a sci-fi racing game in the likes of F-Zero or wipEout but with one difference: you do not race on tracks but in a corridor. This means, you can fly up and down as well as left and right. Of course the corridor may sometimes be huge (in a city or a big cave for instance), but sometimes it will be narrow (when being in tubes or something). It's all about obstacles, skills, competition and a big bunch of weapons.
Another important thing about ZeroG is the strong focus on the multiplayer part of the game. Besides classic modes like normal races, championships, career and so on, the game has some quite new and interesting multiplayer features like coop-play or track-actor.
The game is open to all platforms from PC to Wii but for the sake of great graphics and a strong multiplayer it should be done on PS3 or XBox360 or PC.

For more details just take a look in the (rough) design document.

overall game design
single player game modes
multi player game modes and online game modes
background story
art design
unique selling points and features
GUI and interface
technical stuff
project planning