Kerbal Space Program is an amazing piece of educational software, because instead of directly teaching players principles of rocket design and orbital mechanics, it causes them to figure out stuff on their own.
Not only does this cause players to learn the basics very quickly, it gives them an intuition for formal education. It's much easier to understand someone explaining an advanced thing about orbital mechanics when you've got experience manipulating orbits.

Would it be viable to make games for other areas of science?
Chemistry would be good, but can a home computer quickly approximate molecule behaviour?