Most games fall apart past six people: turns take forever and half the room is waiting. With phone-based games everyone plays at the same time, so a group of 12 moves as fast as a group of 3. Anyone else can join as a spectator and watch on a TV or their own phone.
Race games are the easiest win for a big group: everyone gets the same puzzle and the leaderboard updates live, so there is no waiting for turns. Reaction Time and Typing Race take seconds to explain. Make 24 and Five Letters suit a group that likes puzzles.
Reaction Time · Typing Race · Make 24 · Five Letters
Imposter, Most Likely To and Would You Rather get better as the group grows: more suspects, more votes and more surprising results. Forbidden Words is a team effort where the whole room counts its cards together.
Imposter · Most Likely To · Would You Rather · Forbidden Words
Chess, Checkers and Four in a Row have a Knockout cup mode: the whole room is drawn into a bracket and matches are played one at a time while everyone watches the board and the bracket. Byes fill odd numbers, so any group size works.
Chess · Four in a Row · Checkers
Party Night plays 3 to 6 games back to back with one running scoreboard, so a big group gets an overall winner at the end of the night. The host picks the lineup, and any game that needs more players than are online is skipped automatically.