1++=no error
0=unknown error
-1=out of memory/ram
-2=failed to open graphics file sprites
-3=failed to open graphics file tiles
-4=could not load level
-5=could not load map
-6=no levelset found
-7=backgrounds not found
-8=
-9=could not initialize grayscale
-10=
-11=
-12=textfile not found
-13=
-14=
-15=
-16=
-17=
-18=
-19=
-20=
