Tetra master def wont ever come back to playonline but it should definitely live on in some other form, either as a standalone game (think hearthstone) with new features or as a phone app as others have suggested. I would have played Tetra Master a lot more than I did if it 1) didn't cost extra money to play and 2) I could play it while playing FFXI at the same time. I think the latter is pretty much what doomed it to failiure, rather than whether or not the game was fun.