Killzone 2 is a FPS for the PlayStation 3, developed by Guerrilla Games and published by Sony Computer Entertainment. As we can see in a very early Killzone 2 multiplayer video from 2006 , the beta version had tons of changes from the final game. Some of the changes include very early maps with differed layouts and themes.
The m80 has a red dot sight and a grenade launcher, the Helghan weapons have white muzzle flashes as in the first game. The way you see your gun in your hands is different and the graphics are nowhere near as polished. It appears that classes haven’t been implemented into the game yet and both sides only have 1 character model. Probaly the biggest and most noticeable difference is that there are drivable vehicles, which are not available in the final games multiplayer.
Thanks to Earthwormjim for the contribution!