steam challenge

xcom enemy within (campaign)
endless space (one game)
gal civ2 (one game)
civ 5 (one game)
orcs must die! (finish)
walking dead (start to finish)
metro 2033 (start to finish)
republic commando (finish campaign)
cave story (start to finish)
shank (start to finish)
super meat boy (start to finish)
don't starve (play until death or one in-game year passes)
binding of isaac (beat mom or until ragequit)
bastion (finish campaign)
deus ex (full game)
torchlight 2 (finish campaign as one class)
red alert 3 (one campaign - soviets, allies or empire)
company of heroes (finish campaign)
darwinia (finish campaign)
empire at war (campaign)
supcom2 (finish campaign)
defcon (one game)
magicka (full game)
left 4 dead 2 (all four campaigns)
monaco (finish campaign, maybe co-op with sk/you guys?)