If installing e.g. the UT 2004 or Quake 4 demo doesn't help, then this should help:
http://ubuntu-gamedev.wikispaces.com...es+development
You can install the packages listed via "sudo apt-get install <package names>"
This will probably install more than you need - development stuff which is used for programming, which you could ignore, but it will probably produce a working copy after all. Maybe the only things that you really need are libsdl-1.2debian and libglu1-mesa-dev, maybe mesa-common-dev and libsdl-net1.2 too. Try installing one by one and experiment.