It seems that I've been returning to this one. Mechanto Force is now getting a unique design, though I'll probably just the "body" as various tiles and use various entities to give off the illusion of the boss using attacks along with an entity for the player to attack.
Also created a new main theme from stitching bits of a few Kokuga tracks together so I'm thinking about expanding the game's intro cutscene. I might consider using another version for the final boss.