Thank you everyone for the amazing interest!
In just a couple of days, all offered states (Spain, Ottoman Empire, Sweden) have been accounted for, USA will probably be released to a new player shortly as well. That leaves us with Belgium, and possibly other nations to be extracted.
I have to say that the default 7 and most of the nations already played are the most interesting to handle in PoN, but this does not mean that you can't have fun manning one or more of the minor ones for some alternate history action. We are planning to mod our game on-the-fly to give some limited colonial options for every minor nation, options that would of course be appropriate to their historical capabilities.
The pace is rather relaxed, one turn per day, so this game is pretty compatible with real life.
Apart from Belgium, other possibly interesting nations to play alone or in combination are: China, Mexico, Denmark, Egypt, Argentina... the possibilities are limitless. If you find the challenge limited, you can man more than one, as long as they don't have historical incompatibilities (or animosity).