Branding it as a game won't solve the issue.  If money is changing hands it always runs afoul of AML & PATRIOT act type laws, game or no game.  We gotta keep them thar terrists in their place and if it means we get to give every citizen of the world a financial rectal exam all the better!

Anyone who thinks they are able to skirt the law in this regard, simply by attempting to reclassify their business as a "game" is sorely mistaken and will end up being spanked by the law at some point. 

Point of fact, a contract requires 3 things; offer, acceptance and consideration.  Consideration is usually money, but can literally be anything.  Courts tend to treat non-money consideration in terms of it's monetary value in a fair and open market.  Thus if you're swapping bonds for BTCs, the open market value of those bonds is the market value of the BTCs.  Trading them requires the exact same (if not more), limitations and verifications as trading against those bonds in local fiat.

I promise you a judge will look at bitcoin and BTC denominated transactions, the exact same way as ANY foreign currency contract.

Your best bet is to incorporate in some foreign country with lax securities laws (idontgiveadamastan), and then set your self up as a proper exchange in THAT country.  Not every country requires compliance with US laws and US law can't really touch you in those countries, they're just damned glad to see some money moving through their country.

banking4bankers.com has some good resources to point you in the right direction.  My current fav if you're a USAian is to start looking at Belize for this sort of thing.