That doesn't make a difference. There's a directory called ".tremulous"(NOTE THE PERIOD IN THE NAME. THAT IS NOT A TYPO!) which can be revealed in Nautilus by going to View -> Show Hidden Files.
However, the problem is most likely because of Compiz. For some reason, recent versions of Compiz in Ubuntu break fullscreen in Tremulus, so the only way to fix it is to kill Compiz and use Metacity while Tremulous is running. Here's a start script I put in my bin directory(/home/me/bin/):
#!/bin/bash
if ps ax | grep -v grep | grep metacity > /dev/null; then
donotreplace="1"
else
donotreplace="0"
fi
if [[ $donotreplace == "0" ]]; then
metacity --replace &
fi
/usr/bin/tremulous +set r_fullscreen 1 "$@"
if [[ $donotreplace == "0" ]]; then
compiz --replace &
fi
This tests for Compiz running, replaces Compiz(if it's running) with Metacity, loads Tremulous(and waits for you to close Tremulous), then replaces Metacity with Compiz after you close Tremulous.
Also, you must apply executable permissions to this script. You can do that with the file properties dialog. Then you run this script(double click). DO NOT run the Tremulous game shortcut in your Applications menu or this script won't work. I recommend naming this script "tremulous" so that when you run it from a console, your shell will prefer this script over just running Tremulous from /usr/bin/.
If someone could improve this, that would be great.
Also, here's the bug report on
Launchpad. There seems to be a better script on there for handling any SDL application(like Tremulous). Both mine and his solutions work.