I found this nice article about prototyping: http://gamesfromwithin.com/prototyping-youre-probably-doing-it-wrong
I think I’ll start this Arbor game by making a prototype. I’ll just try to make one branch with a leaf that you can click and drag. You draw a curvy line while you’re dragging. After you release the drag, the branch will grow to the shape of your line.
That bit is the only part of the design that seems difficult. If I can get that done, the rest won’t be too much of a challenge, besides making it look nice, of course. That’s always the most frustrating part.