I have played several minigames past level 70 , Night bug, and I have also gone beyond level 110 in one game. for most games they level out after they reach a certain difficulty.
for example in the Night Bug game with ed, at some point it stops adding more bugs, and the boards just repeat. for Shutterbug and the library game it also reaches a point where the boards just repeat.
Basically the games go on until you die, or quit. I usually quit once I reach the high score, and then go back to a game when waiting for the new updates.
I hope this helps answer your question.
Monty
