That's a real deal!
I just played on emulation, but it still is impressive how it plays on the mega drive hardware (emulated, in my case).
The sound is amazing, and giving the player a choice of slowing the ship down on the maze stages and get it up at the open ones was a great design choice.
Yes, it is hard and unforgiven, but I think that was the idea, right?
I mean, every shmup on the 16bit era was difficult as hell!
Congratulations on the great work. This is a real 16bit shmup!