It is believed that this is the last version of the game that
was worked on before it was abandoned. It's complete
playable and only needs a few bug fixes and the implementation
of random board layouts to be complete. It is unlikely
these final tweaks were ever done.
So they're planting grass in the ocean?
In the Invisible variation you can't see where
you've already bombed
Limited bombs and miss penalties...
The later variations combine all the various rules