anchor.diff: -{ stdenv, fetchurl, pkgconfig, SDL, libpng, zlib, xz, freetype, fontconfig }:
  +{ stdenv, fetchurl, fetchzip, pkgconfig, SDL, libpng, zlib, xz, freetype, fontconfig
  +, withOpenGFX ? true, withOpenSFX ? true, withOpenMSX ? true
  +}:
   
  +let
  +  opengfx = fetchzip {
  +    url = "http://binaries.openttd.org/extra/opengfx/0.5.2/opengfx-0.5.2-all.zip";
  +    sha256 = "1sjzwl8wfdj0izlx2qdq15bqiy1vzq7gq7drydfwwryk173ig5sa";
  +  };
  +
  +  opensfx = fetchzip {
  +    url = "http://binaries.openttd.org/extra/opensfx/0.2.3/opensfx-0.2.3-all.zip";
  +    sha256 = "1bb167kszdd6dqbcdjrxxwab6b7y7jilhzi3qijdhprpm5gf1lp3";
  +  };
  +
  +  openmsx = fetchzip {
  +    url = "http://binaries.openttd.org/extra/openmsx/0.3.1/openmsx-0.3.1-all.zip";
  +    sha256 = "0qnmfzz0v8vxrrvxnm7szphrlrlvhkwn3y92b4iy0b4b6yam0yd4";
  +  };
  +
  +in
   stdenv.mkDerivation rec {
     name = "openttd-${version}";
     version = "1.5.3";
  
positive.code:     homepage = http://www.openttd.org/;
      license = stdenv.lib.licenses.gpl2;
      platforms = stdenv.lib.platforms.unix;
      maintainers = with stdenv.lib.maintainers; [ jcumming the-kenny ];
    };
  }
  
negative.code: 
    postInstall = ''
      mv $out/games/ $out/bin
  
      ${stdenv.lib.optionalString withOpenGFX ''
        cp ${opengfx}/* $out/share/games/openttd/baseset
      ''}
  
      mkdir -p $out/share/games/openttd/data
  
      ${stdenv.lib.optionalString withOpenSFX ''
        cp ${opensfx}/*.{obs,cat} $out/share/games/openttd/data
      ''}
  
      ${stdenv.lib.optionalString withOpenMSX ''
        cp ${openmsx}/*.{obm,mid} $out/share/games/openttd/data
      ''}
    '';
  
    meta = {
  