Versions below 1.5 had a slightly different map format than versions 1.5 and above, which means that attempting to load a map created in a previous version will result in a horrific crash.  However, I made a little program that will convert the old maps.

The program (mapconvert, in the maps folder), will take every map file listed in maplist.txt and change them so that they work with this new version.  However, if you attempt to run mapconvert on a map file that has already been converted, that file will be really messed up.

Saved game files from previous versions, naturally, are also incompatible.