A new expansion kit compatible with the entire Action-Reaction range so you can create even more spectacular circuits! Construct thrilling circuits, defy gravity with the incredible loop-the-loop and watch as your marbles speed off at high velocity! Fire up your imagination and create even more exciting circuits! A new expansion kit compatible with the entire Action-Reaction range! Add fun special effects to your circuits and further sharpen your ability to hit the bulls eye! Create even more spectacular circuits and jump into the world of physics in a simple and entertaining way!