Here is the beginning of the implementation of the first on these four, seen on the upper left in the photo above:
It's slow going, because it isn't just a matter of putting the planets where I want them and being done. I build the levels piece by piece, and play it as I go. A lot of fine tuning goes into the positions and the masses of planets to give the right feel and motion for play. It's tough, but this level is about 3/4 complete, and there are only three left to go.
However, I'm taking my GRE on Monday, and I have to devote as much time as I can to that over the next three days, so Chromovis is going on a slight hiatus. I keep making small tweaks, such as an introduction screen I implemented today, so I'm putting a definite complete date as next Friday. Then begins the app approval process. Wish me luck.