You know what? You can actually press the start button. Instructions: 1. Right click with the mouse outside the screen. 2. Press the start button immediately. 3. The start button will say "Hello!" for 2 seconds, which proven the sprite was really clicked.
Thanks for oogcon for making this troll, but it wasn't effective enough. This trick was also used by @JamesOuO in Troll Test and Troll Test 2.0 Troll Test: https://scratch.mit.edu/projects/14649859/