Celebration of Twistedness

The Celebration of Twistedness is an event that happens every time Mario loses a 'life'. He is brought before Bowser to be executed, only to be saved by Luigi at the last second. It has never occured to Bowser to just have Mario shot on the spot, instead, he throws a massive party and invites everyone which means that Luigi has plenty of time to rescue his brother.

The form of execution changes every time, apparently.