I finally managed to download and install it manually, but when I tried to run it from the "Games" menu nothing seemed to happen, so I tried running it in terminal mode with the following result:
doctor:$ usr/bin/fgfs --geometry=1024x768 --enable-game-mode
bash: usr/bin/fgfs: No such file or directory
DESPITE the fact that there IS a file in that sub-directory by that name. So what do you suggest I do to get it working (and yes, I have installed the dependencies the documentation for it says I need)?