Board Thread:General Discussion/@comment-25324366-20160802162300/@comment-5670246-20170208220038

Punctuation Penguin wrote: During the fight with So Sorry it says that it has friends/a friend whom if you kill, you Level Up. When you kill Sans, you automatically level up to level 20. Also, in Song That Might Play When You Fight Sans, at 0:34, you can hear a noise in the background which plays at the beginning of Wrong Enemy!? Discuss

That "sound" you heard is called a leitmotif. Said sound would never have a connection between the two.