Weight... so that you can have a scale say 0-9 0 being a balloon filled with helium that would slowley rise, and 9 being say steel, this would add greatly to the physics.
Variable Gravity, 0-9 0 being no gravity and 9 being full gravity this could be turned on and off at points thoughout your game.
Wind: again say 0-9 and direction this would also add greatly to the physics for puzzle type games and say vehicle games where jumps are used. Maybe in your game you have to position fans etc to blow objects to certain areas.
Bouyance if thats how its spealt.... Again for water type physics.
Anyway thanks for a great product easily the best value for money compared to other products on the market. Can't wait for the next 12 months to see this product really grow.