Found out that you are allowed to update games submitted to Game Off...

Major changes:

• Parallax background added
• Holding up now allows the player to hover-jump: jumping at the exact same spot every time
• Power up item no longer fly all the way across the room, encouraging the player to take risks to collect it

Other change(s):

• Jumping/shooting sound from the character has been reduced by 10 dB due to many complains