First off great work!!

Installed PrBoom from extras, removed all but "prboom.wad" from /opt/doom/wads, copied in doom.wad had a play around, then removed doom.wad and copied in doom2.wad, again works great!

Installed the accelerometer GUI that works great too (left a comment on that thread)

BTW: found using the acc for forward and back and the left/right arrows for left and right works really well as an alternative to just using the acc