Friday Night Funkin' vs Sonic is a Friday Night Funkin mod in which Boyfriend enters a random Sonic Rom hack game and starts a rap battle singing to the beat of Too-Slow.
There is a new mechanic with two different worlds: The normal world and the EXE world.
When you are in the normal world, press the "Yellow Ring Notes". But the game shifts to the EXE world when the opponent hits the "Static Note". In the EXE world all the "Yellow Ring Notes" become "Red Ring Notes", so you must avoid them. You can only return to the normal world mode by hitting the "Square Static Note".
The reason you want to hit the "Yellow Rings Notes" in normal mode is that it will insulate you from taking damage in EXE world mode if you accidentally hit the "Red Ring Notes". Because if you have zero rings and accidentally hit the red ring notes it will take away a lot of health.