Nerf Arena Blast is based on the play toys of the same name, and combines the blast 'em up action of Quake with non-violent gameplay.
There are three game modes to choose from, including Pointblast (the person with the most points wins), Speedblast (collect seven flags, while getting rid of the opposition) and Ballblast (score a set of balls into hoops around the arena, while keeping the enemy at bay). Each mode is played on a range of different landscapes, including a Space Station (complete with anti-gravity and an airlock, plus plenty of asteroids).
Weapons range from standard blasters each with secondary functions to high tech gadgets, including the Ballzooka which fires high impact balls and as a secondary function fires goo which sticks the opposing player in place for a few seconds, giving you some time to take him/her out of the game.
Nerf Arena Blast uses the multiplayer engine from Unreal. This is particularly ironic because one of the biggest complaints about multiplayer Unreal was that the guns were so underpowered it was like trying to kill your enemies with Nerf weapons.