There was something sort of like this in ffxi called goblin mazes, you could set up a general layout for yoir own mini-maze and fill it with a monster type of your choosing. It was actually fun.

It would be neat if they brought it back. And pankration for that matter (think pokemon in a gladiator pit using in game monsters.)

There are so many things that they could add to the game honestly *tetra master would be nice, blitzball, chocobo hot and cold, if only they were made to be entertaining and rewarding and not things people would do for a few days then move on like the gold saucer...