Hi Martin,
The exehdr command should have turned the exe into a PM app with no console, which I see your build does. Perhaps you added a DEF to get the same results, in which case you could also add bldlevel info.
The binary seems to work fine here.
The text file has a couple of issues, the reference to "SET INCLUDE=C:\usr\include" could have "or similar" added, not everyone installs to C: The link at the bottom is for mirrormagic instead of rocksndiamonds.
Also I don't see any source or patches, I assume you will add that.
I'm still trying to get a version of sdl2 mixer with mod support