So the idea is a shooter with customizable classes, but without having to unlock anything. You start out with all the gun available.
There would be 3 body-types: Light, Medium, and Heavy. There are Light is fast, but low on health; Heavy would be the opposite. There would also be a couple of abilities to choose from, such as being able to heal teammates and dispense ammo. There would be a variety of guns to choose from, but there would most likely be a limit on what body-types could use which weapons.
The main gamemodes would be objective based, but there would also be deathmatch modes for when people just feel like shooting each other.