Hi. Sorry for the late reply. Thank you for the cartridge version. Really awesome. I have tried out the game on the GX4000. It does work. I already played some levels.
I would have two suggestions. The game seems to skip the title screen by itself. I can barely see it before I'm already in the main menu. Also, the game starts automatically after a short time. Is there a way to set this up so that you can press fire button 1 to skip the title screen and start the game? The second thing would be, if it is possible, that the jump can also (additionally to "up") be placed on the Fire Button 2 of the joypad. This would be useful for CPC Plus and GX4000 users, because the devices support two buttons.