It's not a bootable disk. To make the game run you need to call PRINCE.EXE from a floppy labelled "PRINCE PC". (If the label isn't correct you'll be told "Key disk not found".)
However trying to run the game causes but a severe crash in DOSBox and also in a Win98 virtual machine, and in DOS 6.22 in the same virtual machine (booting from a DOSv6 floppy). Other devices could be tried, but anyway this doesn't look very playable in practice for the average abandoneer.
I have no idea whether this is supposed to run well in some system from Stone Age or the file is corrupt. Can Ermuli himself play it?