I'm not complaining, hell, I'm playing the game and it's surprisingly fun for such a simple concept!

Maybe the ethics question depends on whether it's individual morality or public policy.

On an individual level, live and let live.  As long a you're not dishonest or coercive, you should be free to do what you want and make your own mistakes.

But from a public policy standpoint, that's a disaster.  What kind of crappy economy would your country have if everyone's just playing pyramid games and trying to get rich quick instead of producing real value?

And the bitcoin games can be a kind of utopia, where there's no deceit or coercion.  The Ponzi operator actually calls it a pyramid, and makes all the transactions public! 

https://spreadsheets.google.com/spreadsheet/ccc?key=0AiID-eW4QPZ_dF8ya3VvQVYzSHpIbzJKVWlMeUxYcnc&hl=en_US&authkey=CPOghYEL

So cool!  That would never happen in the real world!

So caveat emptor, keep it honest, and game on!