Sentient circles don't roll as much because they don't want to fall off, squares unthinkingly don't care.
Watched your solutions to the lvls, 38 can be solved easier (in my opinion) by quickly blasting the good guy up the ramp, encasing it in a nice layer of squares, removes the timing.
 "Memohuntress"){kind=icon}
 "Blow Things Up!"){kind=icon}