for 64 bit Ubuntu 12.04 & 12.10. Full version free to play. A lot of bugs fixed and added options to command your pet dog.
The official home page at Unrealworld.fi holds packages also for OpenSuse and for 32/64 bit versions for Ubuntu 10.04, 10.10, 11.04, 11.10, Linux mint 9-12, Debian 6.0 squeeze, Debian 7.0 wheezy. There are also tarball versions without SDL libraries included.