64-bit Windows has no problem with 32-bit software, and this little game doesn't go anywhere near the memory limitation of 32 bit, so there was no reason to make it less compatible (many Windows users are still on 32 bit, since there seems to be a dislike of updating in the Windows community). I didn't realize it was an issue for Linux, or even that the universal option existed.
Anyway, Linux version is updated. Feel free to redownload. :)