"Main Theme (OST Version)" is a rip from Mighty No. 9.
The rip is a midi swap of mm2wood.
At the 1:18, an Avast error message appears warning that the video is infected with "URL:piece_of_shit_game". The text-to-speech voice "JerkFace" from VoiceForge (the voice used to represent SiIvaGunner) accompanies the message with "Caution: A virus has been detected".
This is a reference to a Tweet from June 2016 showing that Avast (a free anti-malware program) thought Mighty No. 9 was a computer virus.