It'd be incredibly limited in scope, especially if a free to play game. Unfortunately paid apps don't get the kind of buzz F2P apps do, so that's likely the way it'd go. Towns would likely be smaller, shops would have less items, you'll likely have to wait a long time to upgrade your house or pay for faster upgrading, likely have to upgrade for more villager housing, etc.
It's not that it can't work, it's just something would taint the overall experience and that's not something you want to do.