But i was wondering if you could look into Rocks & Diamonds.
It would benefit many users in many ways such as
a) It has customisable levels and even zelda levels
b) Boulderdash, Supaflex, Sokoban and Rock's & diamonds level sets
c) AFAIK no emulator plays any of these games well enough yet (Boulderdash takes forever to load and its emulated).
d) capability of playing two players
Hoping you would find interest that is if i can't port it :P