For this project, experience has taught me to design almost everything before working on the art. Here is a screenshot of one of the latest levels...
As you can see, there are are now six colors/cursors to use. The square boxes can be destroyed simply by clicking on them with its corresponding cursor based on color, and the green circles constantly spin in a particular direction. Of course none of this this is represented, but these new features will be clear and obvious once I spend a couple days on an art pass. In other levels I have introduced "dead regions" where cursors cannot interact with anything and it has opened up many level design possibilities.
It may not seem like it, but designing levels for these 2D games actually is very time consuming. It takes a lot of trial and error, and I have come up with the best levels by randomly placing objects until I see something that can be refined. It is similar to the challenges that writers and painters face when it comes to creating great composition. Fortunately it is a skill that can be improved through many hours of effort.
The bunny defense game will be continued immediately after finishing this sequel. All the features are finished, so it just needs some careful balancing and additional audio.
For what it's worth, here is an in-game screenshot of one of the prototypes from earlier this month. It functions just like Crayon Physics, but features chalk and strings.
And here is a different prototype that involved bouncing droplets into a flower vase using platforms, balloons, and umbrellas. Actually it played well, so I may come back to it.