SineTuner

You control the red and green sine curves at the top. The blue curve at the bottom is the average of these sine curves. The yellow curve is the solution curve. Try and make the blue curve coincide with the yellow one. Click and drag the meters at the button to adjust the value they represent. Click the switches to the right to toggle the sine waves on and off. This game is still in alpha and by no means finished, but you can play it in its current form.