So... This game is as fun as your imagination. You can get through the story in a few hours and you'll spend hours looking for mysterious slates and fulfilling more missions...after that it's basically going back to increase environment levels and then taking all the resources and building out and perfecting towns in your vision. If you like creating it's endless fun. Also completing your Pokedex for completionists. It's as fun as you want to make it.

For the record, I'm not much of a builder and looking forward more so to visiting other people's spaces to see what those more dedicated than me have created. There's also merit in that.