Although to its credit Nicktoons Unite doesn't stonewall you at the final boss and force you to grind its tedious levels over and over to stand a chance
The lead designer when they asked the art team to design a boss to replace one of the reused bosses from the original and they bring back a robot version of Birdo: "Woo hoo! Just what I needed!"
Absolutely Scientifically proven that playing through these games with another person will cause you to form a lifelong unbreakable soul bond with that person. I will not do a formal study on this.