The apprentice missions by arramus is a 3map single player minigame. u kan download here..
also crater by rc-1266 is good and u kan play co-op tdm dm it featues ai
also the ordmantel 2maps install.. just start loadgame save and open console in game type open omt_o1a.ctm ,hit enter and itl switch to that map...
normally that is only 1map sumtimes called order66
also a short campaign called SE_CAMPAIGN by a french guy volgore not available now
just install and then start a loadgame save and ingmae open console and type
open SE_01briefing.ctm ,hit enter and itl switch to that map
also a single player short mission by volgore also i think called DM_WAR_TRONDO_EPSILON u kan download it here and in single player lan u create a lan server start then open console and type open dm_war_trondo_epsilon.ctm , hit enter and itl switch to that map
also DM_epsilon_2 same process but in console type open dm_epsilon_2.ctm
ifin doubt goto your maps folder and write down the exact names of the maps youve installed to make it easier