I was able to get this to work by downloading the mac version and the windows version and moving the .pck file from the mac version over to the windows install, it looks like only the Mac upload has all the game files present.
FYI, if you walk too far into the river you fall through the world forever, you might want to put some barriers here. I also couldn't find a way to quit the game, I had to alt-F4 out of it.