I can see both sides of the "game" argument. On the one hand, the term game can help people understand what Ray described above -- that BDSM can look non-consensual or dubiously consensual or damaging but it's not. "Game" is more approachable than the phrase "mutually supportive and negotiated relationship construct", even if the latter might be more accurate for a given situation. And it doesn't necessarily need to the trivialising... consider the phrase "game of life". That said, I can see how it would be too unserious in connotation for some folks. I probably wouldn't use it myself in some cases, though in plenty others I would.
In my internal world of turn-ons, dreams, and desires, BD and S&M are subordinate (heh) to D/s. I understand that this makes me more confusing and worrying for people who can understand at least a little the idea of someone getting spanked or tied up because they like it, but who see all that psychological stuff as sad, sick, unhealthy and otherwise highly problematic.
In my blog, I just posted a personal D/s manifesto. It covers how I got here, what it means to me, and what I wish for.
Part 1: http://www.polyamory.com/forum/showp...&postcount=201
Part 2: http://www.polyamory.com/forum/showp...&postcount=202