Seems as though all of you have at least one thing wrong.
First: no, there's no scoring system.
Second: yes, the whole idea of Nano Lasers is to figure out what you need to do; actually doing it is really easy.
Third: the goal is to hit the target with the laser. To do this, you need to configure the arrows so that the laser will hit it, and make the laser travel for long enough that the object blocking the target can disappear. The laser dissipates over time, so you need to have it pass both of the squares at the right time, and the squares need to be activated for this.
Fourth: nothing really happens when you "win."