I got the Racket + Game of Life demo to work on a 50 x 50 grid at a framerate that was semi-tolerable, and by semi-tolerable I mean 10 FPS on this ancient machine. I guess that's 2500 sprites on a 1000 by 1000 canvas, and I'm redrawing the whole thing every time (but now onto the same bitmap). A 30 x 30 grid, on the other hand, is plenty fast.

The slow bit at this point is the blitting of each sprite onto the canvas.