Gameplay consists of aligning the 4 base chemicals of DNA (adenosine, cytosine, guanine, and thymine) into symbol pairs (AT & CG) by using the arrow keys on the keyboard. Use left and right arrows to slide the current symbol over its appropriate mate, and press space or down arrow to drop it. Each pair that slides off the left edge of the play field adds one yellow light to the score display. But if you miss even one, your progress is erased and you must start again. Make use of the upper left and right corners to store symbols, and to trade the current symbol with the one stored there.
A delightfully designed game with an educational slant, DNA Factory is fun, charming, and a bit challenging for a short little diversion.