I tried again, and the right mouse button probably worked the first time, but it seems that it only works when all the cubes are “ready” to accept my click. I get the feeling that either the delay between clicks on the cubes is too long, or it is unnecessary. What I mean is:
I clicked on the cubes and want to click on something else, but I have to wait (not long, but I feel like I have to wait).
P.S. Please don't take my comment the wrong way, I'm just sharing my impressions.