Writing screen savers was a lot of fun too. There are some constraints, but you have a blank canvas. I wrote a rock climbing screen saver in the late 90s that u

Writing screen savers was a lot of fun too. There are some constraints, but you have a blank canvas. I wrote a rock climbing screen saver in the late 90s that used a very simplistic inverse kinematics model to animate a couple of climbers trying to find a route up your screen. I've long since lost the source, but it would be fun to rewrite, there's just nothing to target