So I've been playing this game on a friend's system who has the GOG version. I fell in love with the game and bought it for myself on Steam. Now I'd kinda like to keep my old save, which is about half way through the game, I reckon. But I can't really seem to figure out how... or if it's even possible.

Here's what I've tried so far (to no avail, obviously):
-Located save file in GOG version ("Shantae and the Pirate's Curse.save" in the folder)
-Located save file in Steam version (steam folder/userdata/[my user number]/345820 (that's Shantae's number)/remote - there's the file that's just called "save", no extension, nothing.
-Tried copying the GOG save into Steams save folder, deleting the Steam save and renaming the GOG save to "save".
-Tried opening both in Notepad, copying data from GOG save into Steam save.

Everything has given me "corrupt save data" on startup.
I fear my computer skills are pretty much at an end here. Does anyone else have any other ideas? Pretty please? =)