What about making it so that once you pass a level you have the option to go to a harder versio of that level. I.e. Taller skyscraper, more carts on ferris wheel, different types of houses, and longer treehouses or more 'children'.
I do like this idea a lot too.
I like this idea it makes a challenge for even the most skilled people
Cain Robinson commented
This is a cool Idea. like on the skyscraper a level Idea would be make it withstand hurricane force winds or even a tornado.
Lucas Norber commented
I really like this idea and it "meshes" well with many peoples thought on making a second part to most levels where people try to build structures that can hold the most weight instead of the cheapest! And it adds a lot of replay ability to the game!
This sounds awesome! It would allow for different highscores as well!!!
I really like it, it would keep the levels fun after you beat them a few times.