(informal, figuratively) to pull out all the stops, to go all out

(game theory) zero-sum game

to get caught up in the game, to take a liking to the game, to get into it, to play along, to get into the swing of things (to start liking to do something)

soggy biscuit (supposed game where men masturbate each other in a circle, ejaculating onto a biscuit, with the last person to ejaculate forced to eat the biscuit)

(figuratively) to play into someone's hands

(figuratively) to play one's cards right; to make it out of a potentially bad situation relatively unscathed; to pull out skilfully while the going is still good

(games, idiomatic) that's not fair game

(figuratively) to play someone's game, to play along with someone, to go along with someone, to get dragged into someone's game

to grin and bear it, to put a brave face on it

(computer games) massively multiplayer online role-playing game