both quake and quake2 are available for the N900. all of this stuff can be manually installed, bit of a pain, but it all works. one only needs the binaries below and the demo or retail game data files.

quake (by pipeline) (runs 800x480 in software, -winsize 800 480 on the command line):
http://talk.maemo.org/showthread.php?t=10064
http://wardenclyffetower.com/MaemoFi...e/sdlquake.htm
http://wardenclyffetower.com/MaemoFiles/sdlquake/

quake2 (including ctf support) (by pipeline):
http://talk.maemo.org/showthread.php?t=20603
http://wardenclyffetower.com/MaemoFiles/quake2/

quake2 mission pack support (by pipeline):
http://talk.maemo.org/showthread.php?t=20603&page=2

quake2 update (by qwerty12) (runs 800x480 in software, +set sw_mode 4 on the command line):
http://talk.maemo.org/showthread.php?t=20603&page=5

xqf multiplayer gameserver browser (port by pipeline):
http://talk.maemo.org/showthread.php?t=19965

many thanks to both pipeline and qwerty12!

being a quakeworld and quake2 player myself, what i'd personally love to see, are arm ports of the greatly enhanced clients used in the competative quake and quake2 communities, with opengl support. sources of these windows/linux clients are ofcourse available as demanded by the gnu gpl.

quake:
ezquake - http://ezquake.sourceforge.net/

quake2:
r1q2 - http://www.r1ch.net/stuff/r1q2/
q2pro - http://skuller.net/q2pro/

anyone up for doing it? :)