Like the name suggests, it is an extremely difficult game. It uses a variety of different Nickelodeon animated characters. Nick.com describes the game as "Played all the games on the site? Are they all too easy for you? Well ok, Superstar Champion Gamer, How about you play Nickelodeon's Hardest Game Ever!"
The game is quite simple, all you need to do is move your mouse, which controls a character. The starting character is SpongeBob and you can unlock characters from four other Nicktoons (The Fairly OddParents, Winx Club, Teenage Mutant Ninja Turtles, and Sanjay and Craig). Balls of slime and other things will fall down from the top of the screen and using your mouse, you need to direct your character (who has a small little platform on their head) to bounce the ball off of the little platform. While it looks quite easy on the surface, throughout the levels, the game gets progressively harder, and to make it even more difficult, once you die, you need to go back to the start.