Multi-player 3D FSP on Emacs
d.hatena.ne.jp
d.hatena.ne.jp
(prepares emacs-user resistant bomb shelter)
Emacs does not come with a lot of features built in, it comes with lots of loadable modules. If you don't need them then don't load them. The notion that Emacs is bloated has not really stood since around 1985.
The power to write a first person maze (which just blew my mind since it appears to be written as a character based hack, rather than an embedded widget) is the same power that allows you to write powerful libraries for modifying text.
http://caca.zoy.org/ http://doom.wikia.com/wiki/Text_Mode_Doom
http://webpages.mr.net/bobz/ttyquake/
(best quote: "If you have to ask why, you're not a member of the intended audience. Please go on about your business and accept my apologies for this distraction.")
and text mode UT configs by Icculus (or: switching the SDL renderer backend to aalib):