First I'd like to say: great game! I have it running in a Xubuntu 12.04 32bit VM very nicely. Just the top menu bar of xfce shows all the time. Minor glitch that.
The host system, however, is an OpenSuSE 12.2 X64 system with 32bit support libraries. Steam downloads the game fine, but when you launch the game, after it gives you the CD key, and asks which version (game or editor), the game never appears. No errors are displayed.
So, opening a terminal and starting the game manually:
~/.steam/steam/SteamApps/common/Unity of Command> bin/uoc
No protocol specified
No protocol specified
No protocol specified
No protocol specified
init kbd.
No protocol specified
xcb_connection_has_error() returned true
there is no soundcard
Ok, so the game can't find sound, not uncommon with 32 bit software. There's unfortunately nothing informative in the output in the terminal, other than those lines it just returns to the prompt. I must be missing some 32bit compat libs?