Move your mouse around and off of the screen. Press 'space' to change the sprite. The sprites will follow your mouse wherever you put it, unlike Scratch's go to mouse-pointer motion block! If you want to use this, just backpack the first sprite and delete all the costumes you don't want except for the first two (these are important, the project won't work without them).
Thanks to @PusheenGames23 for the accurate mouse XY limit workaround.
