If you have a device with lot of dynamic memory and UDMH you might like to try my latest port: Hexen2!!!! As usually you will need the pak files from the original game. Read my website for installation instructions: http://www.metaviewsoft.de/
Known bugs are (among others): Sound is not working, Music neither.
Hexen 2 is a Quake 1 engine and therefore it was quite fast to do, except from two bugs which drived me mad... One of it was even in the original port I've made this port of. But this port shows the problematic we will run into when one would try to port Quake 2: Memory. ZHexen2 needs around 14 MB dynamic memory. Something you will probably only get on a T3, TC or the Zodiac in conection with UDMH. I believe it's impossible to run it on a TX or even a T5. This devices doesn't even have so much real memory free to use. Prove me wrong and I'll invite you to a cokkie :-)
As far as I know Palm OS is the only known mobile OS, which does have an Hexen 2 port yet :-) Grab your copy from http://www.metaviewsoft.de/.
Enjoy! Henk.