N2O is a shooter in the same vein as Tempest and Nanotek Warrior. You pick from one of five ships, each of which has different turning and braking speeds, and shoot a bunch of eggs and bugs that travel through a large tube. While the graphics are decent, the only thing N2O truly has going for it is the soundtrack.
The gameplay is straight-up Tempest. You travel around the inside of a tube and shoot at everything in your way. If things get too hectic, you can slam on the brakes, stopping your forward movement for a few seconds, which should give you the time to clear a path. Once you've destroyed all the level's eggs, you progress on to the next tube. If it sounds basic, that's because it is. You just keep plodding on from tube to tube. Occasionally you'll face a boss to break up the monotony. At least the loading times are nearly nonexistent.
The graphics in N2O are about what you'd expect: a fast-moving polygonal tube textured with wildly colored cycling patterns, as well as polygonal enemies. The game has some pretty good lighting effects, as well. The game's soundtrack is provided by the Crystal Method. Many of the tracks were taken directly from their album, but there are a few remixes on the disc, too. The disc's audio is in redbook format, so you can pop it into any audio CD player and listen to the music. Normally this wouldn't be such a big deal, but since Fox seems so bent on pushing the game solely on the strength of its music, it's worth mentioning.
As a game, N2O is decent, but it really isn't worth purchasing. If you're really into the soundtrack, you'd be better off spending 15 bucks on the Crystal Method's album instead of spending ducats on N2O.