The London Science Museum launched (pun intended) a Flash-based webgame called "Launchball". It became popular enough that there is now an app for the iPhone.
Launchball is a physics puzzler where you need to get a ball from Point A to Point B using the tools at hand. These tools include fans, magnets, tesla coils, bunsen burners and much more. Each tool is introduced in sequential fashion during the introductory levels and in general feels much more accessible than similar games we've played. Once you set up the board as you want, you can press "start" to set the scene in motion to see if you've succeeded.
You can find the Flash-based web version of the game here.