b h - 2009-04-07

I have Ubuntu 9.04.  When I run prboom (prboom -vidmode gl -iwad doom2.wad), it looks like it is loading doom2.wad (the shell output says so) but I cannot play any of the doom2 maps. I am stuck with what look like deathmatch maps. They contain only weapons, no enemies.

How do I play the doom2 maps?