Awww.. and now it works!
However, my game has more bugs.
I want to draw 3 random elements (without repetition of colors). Construct 2 actually draws me 3 elements, but sometimes imposes them on itself. That's no good. I honestly did not know how to solve this problem.
It seems to me I have to read the position of object (when it is created), save it in a variable and in the next iteration check that has not previously been used, right? That's is the only thing that comes to my mind.
My system of comparing frames is not perfect too, because the application always add 1 to the global variable " points" - no matter what object I choose.
I clean up some code to be more readable.