Comments - complete_

its on steam!
go to Store.steampowered.com or just Install :)

it should work for any "source" game, i believe (such as free tf2)

woah this map looks really good (nice ts overlay you got there)

oh wow that's pretty barren. i guess you were on at the wrong time or something... there's about 30 on right now

Nope! Definitely not dead.

to fix the invalid steam ticket error, try deleting ClientRegistry.blob
if that doesnt work, try deleting your userdata folder in Steam/userdata (it seems to be a problem with most mods)

Well, I haven't been able to play for a month so I don't know the current condition, but I just checked and theres about 30 people on the VIPER server right now. So, It may be a problem with your server browser. Try putting "connect 99.198.97.162:27105" into your console and it should connect you directly to the VIPER sever (It's usually the one everyone plays on anyways).

Great game. Still active and there is usually a full server of players on most of the day. Remember, don't download the Desura or 2.3 Client, you want the one on Store.steampowered.com

there used to be. it just wasnt uploaded to moddb. new version is on steam now

There are many servers. Problem on your end.