Trivia : This game has be redone 3 times by its programmer. The first version was very close to the arcade, and was using 8mb of ram. Unfortunately, he had to make it work with only 2mb of ram. so off the 3rd layer, color reduction.
The game seems to have all the sprite frames kept however.
The system disk is using the same protection as the one SPS used on Marchen Maze :
Disk Protection.jpg
it uses 11 sectors, 8 normal 1024 bytes + 3 custom.