This page details bugs of Abadox.
This projectile that appears in stage 3 uses the wrong tile for one of its two frames. It is programmed to use tile 80, though it should actually use tile 82.
The teleporter/airlock on the ship in the intro uses (quite obviously) the wrong tiles. It uses tiles 23, 24, and 25 (parts of Parasitis' mouth from stage 1-2), though it should actually use tiles A3, A4, and A5.