Nickelodeon Level Builder (lost Flash game; 2010s)
In the 2010s, there was a Nick.com Flash game known as the SpongeBob SquarePants Level Builder. This Flash game allowed users to create their own levels using SpongeBob inspired assets. Several variants of this creator were released, based on iCarly, The Penguins of Madagascar, Avatar: The Last Airbender, and Fanboy and Chum Chum.
Two different versions were released. The first version had a much smaller frame than the second version, but it included checkpoints, along with the ability to change the character and background that appeared on the level's title screen. The second version had a much wider and larger frame and a revamped interface, but removed checkpoints and the ability to change the title screen in any way. It's believed the way the title screen looked depending on the character you chose for the level. The player could choose which character you choose play as, and all of them play identically with double jumps.
The games were removed from the site a few years later, making them unplayable. However, the games can still be accessed, but are buried in the site. The catch is, you can't actually play the games, as an error message will pop up. This is because the site is attempting to load the .swf files, but it can't. The closest thing to evidence of this game existing is a few images and a gameplay video by superjonesbros789856 showing off the SpongeBob version of the level builder.