Since we now know from the digital version of GOLDEN AXE THE MUSIC that Masafumi Ogata composed a couple tracks, the question is if he's uncredited or if he's in special thanks. I'd guess GAS GES GOS, but the other option is U (although that doesn't seem likely, and could very well be original game planner Makoto Uchida).
http://www.vgmuseum.com/end/genesis/a/goldaxe2.htm