Investor-based games
Games where the main factor is whether or not new "investors" join the game. Also any Bitcoin-denominated investment product with an APR of 15% or more, which are similarly risky even if they're not actually paying interest using investor deposits.
Also, are any actual users of the Gambling section irritated by this, or are people just trying to hide this kind of game? Is anyone
against the creation of this section?
I guess you can just create an alt forum in Marketplace named "Other". Also I'm not against that.