From Cubiform Games Lab:
If you think physics is boring, we can prove you wrong. Lightspeed, a game once born in a research lab, is now becoming more and more popular. The game rules are really quite simple. There is a light source that emits light (laser ray). You have different game elements that can absorb, reflect, refract, or transmit light. Your job is to manipulate them (move and rotate) to illuminate all spheres present in the game level. It may sound simple (and it is at the very beginning), but the game gets to be increasingly complex and engaging as you move further. The game is quite reminiscent of the once very popular Incredible Machine and is equally addictive. If you really fall in love with the game, you don't have to worry about the game ever ending, because Lightspeed comes with own built-in level editor.