Garys mod? Zombie Panic?
 

Does anyone know how I might be able to play these games without a steam account and all that junk?

I played them a few years back on a friends PC, and feel like reliving the nostalgia. Thanks you very much

Isn't it Zombie Horde? I thought you coudln't play Source without steam account. G

o download cracked one from torrents or something since that's what my friend does @ lan parties. (When hes hosting that is.)