Algodoo

Nice job on the scene!
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Suggestion: There is a much better way to control the engine rotation than to tell people to change velocity and then to freeze it! That alone will confuse many of the young kids who have no idea what you are talking about. So, a better way is to uncheck the "toggle" checkbox for both thrusters. That way, they can press and hold the "Shift" key to accelerate the engine, and then release the "Shift" key to slow it down. Easy peasy!