What do you want to create? Pick anything. What would be fun about that? Your question is that broad. There are many, many, many axes of difference to explore.

What do you want to create? Pick anything. What would be fun about that? Your question is that broad. There are many, many, many axes of difference to explore. Another way to look at it is "what's fun to you?" If you can't think of anything, you're out of luck. If you can think of anything at all, incorporate some coding.