I've always thought it was a shame this was never ported the the Engine. There's a thread here:
http://www.retrocollect.com/forum/viewtopic.php?f=3&t=1948 where a guy is suggesting a new version which adds in 4 players, a level editor etc.
How hard would this be to write, and what would be the best approach?
I mean the sprites should be freely available, and there's no doubt the PCE could handle it. The difficulty would be the hidden mechanics, such as the route of the bubbles and all the triggers, but these are all available in one form or another.
I just think it would be ultra sweet to have this on a Hu Card.