@Sting : I could not rip the files because i'm not used at all to do that.
Well after going on the ressourced BT.PRG, i have not seen any hardware register for Blitter, nor scrolling. This game relies only on the main processor to deal with display.
To me it's the equivalent to R-type CPC (the CPC version is an emulation of the spectrum version), Black tiger Amiga is almost an emulation of the atari ST version.
About what i said about "ST fanboy". Just tell me how a coder could be good at coding in 68000 on an ST, and being bad at coding in 68000 for the amiga ?
Note also that the coder was whining about "We could do a 32 colors version, but it would means redrawing the graphics from scratch which would take ages. If we'd done the amiga version first then we'd probably have used 32 colors and cut them down to 16 for the ST - It's something we're bearing in mind for the future.".
The game was sold on ST for 19.99 pounds on 2 disks, and for 24.99 pounds for amiga on 1 disk.
This reminds me that we had to pay more for a game on amiga that was most of the time an ST port.
About the copy protection, yep, i saw it, so i just posted
In the same vein, you have the rainbow islands case. Have seen some coin-op screens, the game display is in 32 colors.
But Steve Turner & A. Braybrook said in an interview, that he couldn't use 32 colors, because he didn't have the computing time to trace the 5th bitplan (minoring the fact that he rewrote the display routine to use the blitter).