It says as much in the Readme, we know :p As for updating it, this is the updated version. So it should run... we've been getting some errors on some Windows PCs though, still working on that.
EDIT We have a new demo up! It's at http://jepe.ptreasures.net/demo.php .
Hopefully this should sort out the problems that were stopping some Windows users from running it, and yu can now warp between maps (the lab in Maplewood and Peachblossom Woods are the two examples we currently have).
Coming next will probably action objects, such as houses, and more actiontiles (signposts, footprints, water). Not to mention a battle engine, which is doing strange things atm.