Well it sure took long enough, but it appears that Left 4 Dead 2 will be the first full retail game to include unlockable rewards for your avatar. The awards functionality which was included in this past Spring’s dashboard update has been poorly utilized to say the least. Only Xbox Live Arcade title ‘Splosion Man currently rewards players with avatar awards. So what can you unlock in Left 4 Dead 2 and how can you do it? I’m glad you asked.
Med Kit: Earned by beating all five campaigns.
Bull Shifters Shirt: earned by winning 10 games of Versus.
A Left 4 Dead 2 shirt: Earned by winning 10 games of Scavenge.
Zombie Hand Shirt: Earned by killing 10,000 Infected.
Depeche Mode Shirt: Earned by rescuing Gnome Chompski from the Dark Carnival
Via Kotaku