codah, Somebody and Lordshiva1948 Thank you all for your replies. Thank you so much.
The timer behavior seems to be the one to go! yay!
But now I have a new puzzling issue.
According to the loops X and Y in numbers, posted to Browser log (Console of browser) it shows the correct sequence: one per row.
But the sprites are generating the whole row, and when that's complete it goes to next.
Why do this happen?
I will try to solve, but meanwhile, here's the capx.
EDIT: corrected minor error i capx.