Design Challenge: The Next Step For Team Fortress 2 Submission

I recently submitted into a game design challenge over on gamecareerguide.com. Here's my submission! Feel free to leave feedback and critiques.

The Basics

Team Fortress 2 Tower Defense will take the classic tower defense genre and turn it into a fast-faced, multiplayer experience. Teams will be broken up into two teams: "Runners" and "Defenders." Like their titles suggest, Defenders will attempt to prevent the Runners from reaching their goal. Runners will be restricted to scouts and Defenders will be restricted to engineers.

Gameplay

Defenders place turrets to prevent the Runners from scoring. Like in regular Team Fortress 2 play, the turrets require metal to build and upgrade. Defenders will not be able to place supply stations, so the supply stations will be provided already on the map. Turrets are Team Fortress classes and are restricted by the level upon which they are placed on (see below). The Upper Level can only be accessed by the Defender team. The Lower Level can be accessed by both teams.

Upon starting a match, the Defenders will be allowed to set up appropriately. After a short period of time, the Runners will be set loose. The goal for the Runners is to reach specially marked areas that will reward them with points. The further the distance, the greater the risk but the Runner will earn more points for his team for reaching this further destination. Once a runner reaches a goal or is killed, he will be teleported back to the spawn for another attempt to score.

The match will consist of 2 rounds. After the first round is completed, the Runners will become Defenders and the Defenders will become Runners. Scoring can only take place when a team is playing as the Runners. Firing will be enabled for both teams. Turrets can be destroyed. Engineers can kill Runners and Runners can kill Engineers. Ammo will not be limited for either team.

With smart, tactical placement of the turrets, the Defenders have the potential to shut out the Runners completely. However, a complete shut-out will not happen often because the Runners have access to multiple ways of countering any turret combination through precise shooting, smart movements, and even an all-out group rush.

Turret Behavior

Upper Level:

            Soldier: Quick Fire Rate, small Area of Effect Damage, smaller knockback
            Sniper: High damage, low rate of fire, Piercing Bullets
            Medic: Slows a single target, chance for temporary freeze
            Demo: Mediocre Fire Rate, Large Area of Effect Damage

Lower Level:

            Heavy: High health, low damage.

            Pyro: Low Health, High Damage in a cone in front of the turret.

            Spy: Invisible to Runners, kills any Runner that passes through this turret.