I noticed in the review that you mentioned Laser Squad Nemesis. You should be able to pick up a copy of the game for about $20 retail which has a single player campaign tacked onto a great multiplayer game. I picked it up on its pedigree and I was not disappointed.
Edit: Forgot to mention that the link to Laser Squad Nemesis doesn't appear to work. Just head to
www.lasersquadnemesis.com to check it out.