I wouldn't class most hobbies as attempts to overcome unnecessary obstacles either -- certainly not playing a musical instrument, where the difficulties are all necessary ones. I might count bird-watching, of the sort where the twitcher's goal is to get as many "ticks" (sightings of different species) as possible, as falling within the definition, but for that very reason I'd regard it as being a game.

One could argue that compulsory games at school are a counterexample to the "voluntary" part. On the other hand, Láadan has a word "rashida": "a non-game, a cruel "playing" that is a game only for the dominant "player" with the power to force others to participate [ra=non- + shida=game]". In the light of that concept, perhaps these are not really games for the children forced to participate.

But whatever nits one can pick in Bernard Suits' definition, I still think it makes a pretty good counter to Wittgenstein's claims about the concept.