Humble Monthly leftover, I already own it and beaten it a couple times. I don't think / have any indications that the key is restricted.
It's the OG Half-Life, in Source, with improvements. Pretty self-explanatory.
6 Comments - Last post 34 seconds ago by wxenomorph
61 Comments - Last post 36 seconds ago by Realtione
2,082 Comments - Last post 4 minutes ago by ipax11
30 Comments - Last post 9 minutes ago by EmeraldTablet
422 Comments - Last post 17 minutes ago by MeguminShiro
860 Comments - Last post 40 minutes ago by sensualshakti
217 Comments - Last post 2 hours ago by canis39
32 Comments - Last post 1 minute ago by SimonSays
2,413 Comments - Last post 6 minutes ago by ObsidianSpire
1,690 Comments - Last post 8 minutes ago by hebert2099
127 Comments - Last post 16 minutes ago by vuorikissa
15,160 Comments - Last post 17 minutes ago by cpj128
18 Comments - Last post 18 minutes ago by aklgupta
30 Comments - Last post 19 minutes ago by aklgupta
Thanks for sharing this, Musskattnuss! :)
Comment has been collapsed.
Thank you for making this giveaway. ^_^
Comment has been collapsed.
Thanks for the chance!
Comment has been collapsed.
Thanks!
Comment has been collapsed.
This comment was deleted 5 years ago.
Comment has been collapsed.
Thank you!
Comment has been collapsed.
Gracias!
Comment has been collapsed.
Thank you!
Comment has been collapsed.
love you so much !!
Comment has been collapsed.
gracias
Comment has been collapsed.
thanks
Comment has been collapsed.
big Thanks
Comment has been collapsed.
Thank you!! I would be really happy to play this.
Comment has been collapsed.
Thank you for this, it's very much appreciated
Comment has been collapsed.
Thank you for Aperture Science!
Comment has been collapsed.
Thx!
Comment has been collapsed.
thx
Comment has been collapsed.
Ohhh !
Comment has been collapsed.