They describe a leaderboard built from server members' shared gaming activity, while actual rollout remains unconfirmed.
When It Appears
“Played {firstGame}” can appear on a server view that ranks shared gaming activity and shows a timed competition when Discord displays an activity sentence naming one recently played game.
What It Means
When “Played {firstGame}” is shown, the current step is presenting an activity sentence naming one recently played game.
A user who saw “Played {firstGame}” in Discord is likely searching to confirm that it means an activity sentence naming one recently played game, where it appears, and which state it describes.