In this game, a random sprite will appear angry if you press the "Spawn" button. You cannot spawn another sprite unless you get rid of the current one. To do that, you must press the wand button to prompt you to choose a spell: "Expelliarmus" or "Avada Kedavra." For easier selection, I’ve assigned numbers to each spell: press 1 for Expelliarmus and 2 for Avada Kedavra.
Thanks to the creator of the sounds for "Expelliarmus" and "Avada Kedavra" and to @aspectsvg for the shiny light vector on the thumbnail.