There's a README included in src/ directory:

Linux
- You MUST remove SDLMain.h and SDLMain.m (those SDLMain files are only for OSX)
- SDL, SDL_image, and SDL_mixer libraries are required (probably available through your regular package manager)
- The following command will compile the game on most systems (run this in the src folder)
g++ -I /usr/include/SDL *.cpp -o rpgdemo -lSDL -lSDL_image -lSDL_mixer
- Move rpgdemo to the resources folder and run it from there

I've tested it and it successfully compiles and runs.

Ok, I'll add it in the next few days

I really liked the idea of this game when I played it two years ago.

I found some levels a bit buggy, and the general balance of the game quite off, but it quite enjoyabe anyway

Alpha 3 is out, and now has mulitplayer :D