One could use to enchant gameplay with little challenge...
First to offer is quite similar to OCC:
Merchant.
You may have one city, you can however use all units and other stuff available, including conquering other powers town;
EXCEPT the ones with "city walls", coz You cannot abandon them.
Point is about getting higher score, and mainly through money.
So choose city-place wisely and start haggling with the local bastards. not so many minuses through killing natives though:)
Revolution shouldnt be tough also...
Privateer.
As Merchant but: Do not use any wagons. Prefer islands to place your fortress. Get rid of every colonist not in work or in army.
And of course, sink every ship You see:)

Try out and submit your saves.
or something...

I do that every game I play...