From Dark Omen Wiki

PRJ File format

The PRJ file format represents the world data (as opposed to the mission-specific data) for a Dark Omen battle.

Overall Structure

The Overall structure of a PRJ File is shown below. It is made up of sections:

Header: The string "Dark Omen Battle File 1.10      " (32 bytes in total, padded with spaces)
'BASE': Indicates the terrain mesh to use
'WATR': Indicates the water mesh to use (if any)
'FURN': Describes the position of external meshes (buildings, trees etc)
'TERR': The terrain heightmap, used for collision detection with the ground
        and possibly has other uses
'ATTR': Attribute flags for parts of the terrain
'EXCL': Unknown function at present
'MUSC': The music to use for this level
'TRAC': Camera tracks for the intro
'EDIT': Unknown function at present