> Man, has any game been implemented more times than Tetris?
Yes, because it's a relatively complex game. My bet's on something much simpler like Rock–paper–scissors which has over 60 implementations just on Rosetta Code: https://rosettacode.org/wiki/Rock-paper-scissors
The "Number reversal game" has more implementations, but that's probably less unambiguously a game and more a special-case of of a programming problem: https://rosettacode.org/wiki/Number_reversal_game