You should do a 100 person trivia long game season based on the floor as a game, since you managed to get 100 for the race I believe this would be an idea that could work. It would be a game where a specific number of players are picked a day to do a trivia 1v1 against someone else near them on the board of 10x10 squares. Winner of the duels claims the tile and the loser is eliminated. The community could help to create the trivia topics that would be assigned at random to each contestant for fairness.