User permissions??
Create group games, chmod to everything in the directory and adduser?
May you need a script to make some links for save users data in '~/'. Mupen are running here with a global configuration. I don't know where I'm wrong, but WITH_HOME=$answer line 342 in configure file don't work in my Debian system.
And never adduser to root...
Take a look:
ilidio@lorelei:02:57:49:/$la /usr/local/games/mupen64-0.5/
total 852K
drwxrwxr-x 5 root games 4,0K 2006-06-06 18:35 .
drwxrwsr-x 4 root staff 4,0K 2006-05-05 15:41 ..
drwxrwxr-x 2 root games 4,0K 2005-08-26 16:16 doc
-rwxrwxr-x 1 root games 1,4K 2005-08-26 16:10 jttl_audio.conf
drwxrwxr-x 2 root games 4,0K 2005-08-26 14:33 lang
-rwxrwxr-x 1 root games 684K 2005-08-26 17:11 mupen64
-rwxrwxr-x 1 root games 663 2006-05-20 23:48 mupen64.conf
-rwxrwxr-x 1 root games 13K 2005-08-27 14:41 mupen64_icon.png
-rwxrwxr-x 1 root games 99K 2006-05-20 23:17 mupen64.ini
drwxrwxr-x 2 root games 4,0K 2006-03-26 01:23 plugins
-rwxrwxr-x 1 root games 351 2006-06-06 18:35 rombrowser.cache
lrwxrwxrwx 1 ilidio games 26 2006-06-06 18:35 save -> /home/ilidio/.mupen64/save
-rwxrwxr-x 1 root games 12K 2005-08-26 14:28 whatsnew.txt