Are You Serious?
Not unlocked yetComplete the game in single player on unmodified serious difficulty.
Bird Hunter
Not unlocked yetKill 20 Harpies with the Sniper rifle.
Burn Baby, Burn
Not unlocked yetBurn 100 enemies to death.
Co-op Beginner
Not unlocked yetComplete any level in co-op.
Co-op Survivor
Not unlocked yetEarn a gold medal on any level in cooperative Survival.
Crunchy
Not unlocked yetKill 100 Kleers with the Cannon.
Fragger
Not unlocked yetFrag a total of 100 players.
Look, it's a secret!
Not unlocked yetFind at least 10 secrets in single player.
Look Ma, I'm a Lumberjack!
Not unlocked yetCut down some trees.
Look Ma, I won!
Not unlocked yetWin a versus match.
Make it count
Not unlocked yetKill at least 30 enemies with a single Serious Bomb.
Medieval Master
Not unlocked yetComplete the Medieval episode in single player or cooperative.
Mine's bigger than yours
Not unlocked yetDestroy an enemy cannon with your own cannon.
Nice Try
Not unlocked yetUse the Flamethrower on a Lava Golem.
Persia Master
Not unlocked yetComplete the Persia episode in single player or cooperative.
Rrrrrrrrrr
Not unlocked yetKill 10 enemies with the Chainsaw without releasing the trigger.
Serious Beginner
Not unlocked yetComplete any level in single player.
Serious Damage
Not unlocked yetKill 100 enemies with Serious Damage active.
Serious Run
Not unlocked yetComplete the game in single player by beating the estimated time on each level.
Serious Sam
Not unlocked yetComplete the game.
South America Master
Not unlocked yetComplete the South America episode in single player or cooperative.
Space Marine
Not unlocked yetKill 200 enemies with the Laser gun.
Survivor
Not unlocked yetEarn a gold medal on any level in single player Survival.
The Beast
Not unlocked yetFinish the Legend of the Beast campaign in single player or cooperative.