Gunman Chronicles is a futuristic first-person shooter computer game using the Half-Life game engine. It was originally planned as a total conversion for Quake; it then switched games to Quake II, followed by another switch to Half-Life, before being spotted by Valve Software and released as a stand-alone retail product in 2000.
Beta release of Sandbot - a bot for Gunman Chronicles and They Hunger. Extract to your Steam/steamapps/common/Half-Life directory.
Could be good.
If you try it let me know how it is. There's still room for improvement (especially the Gunman Chronicles part of it - the bots don't use any of the extra features of the weapons yet) but it's usable.