Users who own this game also own:

Left 4 Dead 2
Left 4 Dead 2
Portal
Portal
Half-Life 2
Half-Life 2
Half-Life 2: Episode One
Half-Life 2: Episode One
Portal 2
Portal 2

Users who love this game also love:

AudioSurf
AudioSurf
FTL: Faster Than Light
FTL: Faster Than Light
Aether
Aether
World of Goo
World of Goo
Braid
Braid