Hello there I have a few suggestions:
The first one is the moon and the sun both have a timeline each. What I mean by this is like any other timeline but you can move the sun/moon like you can do in background but its on a timeline. So at lets say: 1:30 you can plot it on the timeline and plot another thing on the timeline at 1:45 and at the 1:45 one you would move the sun or moon. So when you play the animation at that timeline the moon/sun will move. Sorry if its confusing .
Another suggestion is horses. Now you may get a lot of these suggestions but its something which will be really cool to have in MIne-Imator is horses. That would be really cool.
Well there are just some suggestions which I hope you take into consideration.
Bye,
GamerMitch