Algodoo

Nice job!

As a suggestion, I think it would be a more complete tutorial if you could also show the light source and the rotating shutter, as used in a film projector. Maybe even show a few frames of a sample movie or cartoon which demonstrates how the image is projected onto a screen and how each frame is broken up by the shutter in order to reduce the flickering effect.

Good suggestion, but don't hold your breath.

No, I won't. That trick didn't work when I was six years old, and it probably won't work now that I'm a little older.