I decided to check out Snap. The first thing I did was create this same project there for a speed/lag comparison. It is weird, Snap lags baly (for me) at about 50-60 clones while Scratch hits its limit with almost zero lag. Here is my Snap project.. https://snap.berkeley.edu/project?user=locomule&project=speed%20test%20-%20Snap%20vs%20Scratch