Hey! The issue was not technical, i did not understand that i had to take a domino from my hand a drop it onto another one from my arm.
I was trying to take one from the arm and drop it on another of the arm, so unable to drag the domino from the arm ^^'.
After countless attempts, I finally figured out that you had to drag them with your hand! But maybe I read the tutorial too quickly!
Totally agree with you ! I don't know if worth the effort but maybe making domino from the hand glow first THEN glow from the arm to suggest to drag from hand to arm, or something like that, but as I told you, I might have skimmed the tutorial a bit too quickly, so the glow thing would be to keep in mind in case other people give you the same feedback :)