I've completed Odyssey. I don't recall any graphics glitches.
I can't recall much about it however. It was back in the late 90s/early 00's. What I do know is, either I completed it through emulation (An early WinUAE or WinFellow), OR I completed it on a real Amiga using ADFs I would have downloaded off the net.
With that said, either your ADFs are screwed or emulation is screwed. I can't really say. I have no idea which ADFs I used. Since then, I've just been using whatever's in TOSEC.
I hope that helps, maybe.