It is using AmigaOS to detect screen mode, it is some years ago I coded this game, check that you have a screen mode 1280x720 in 32 bits, try open this in your Workbench see that it works, maybe some librarys in your Workbench is old/incompatible. P96 v2.0 is used
Game starts in window mode and as long your Workbench has at least 1280x720 it should just open. If you referring to F full screen mode then above first part only.