Click the flag to be MESMERIZED!!! Also, if you want to change the speed of the lights, press the up arrow. To get rid of the slider, press the down arrow.
Idea from a good ol' pal called KatMe0ws! Also the music is from a remix of a song from Undertale, so credit to Toby Fox (Composer) and insaneintherainmusic (Remixer) ;)