"To play a game is to engage in activity directed toward bringing about a specific state of affairs, using only means permitted by specific rules, where the means permitted by the rules are more limited in scope than they would be in the absence of the rules, and where the sole reason for accepting such limitation is to make possible such activity."

Suits, B. (1967). What is a Game? Philosophy of Science, 34(2), 148-156. doi:10.1086/288138

To me, that all checks out with Manifold. Interestingly, the author also asserts that it is possible that "life itself is a game".

Wiki: A game is a structured form of play, usually undertaken for entertainment or fun, and sometimes used as an educational tool.

Unless you’re on Manifold despite deriving now pleasure or enjoyment from it, it seems to fit the description.

Yes.