You passed 6 whole weeks full of strong antagonists, dynamic battles and cool songs. It’s time to beat the final boss and reach the end of this game! He is a brave soldier with fantastic singing skills. So you totally need help to beat him.
Call your best friend and start singing together. Press the arrows keys in time to hit the right note, pass three songs and reach the victory. The enemy is powerful, so you can switch the difficulty levels and improve your skills there. Train in the built-in endless mode and fight to get your ending. Good luck!