The protagonist also has a few transformations of his own, which serve as the in-universe justification for standard 3D platformer abilities. The game follows Robin, Kermit's nephew who has to go on an adventure to rescue the Muppets who have been transformed into monsters. Muppet Monster Adventure is, naturally, a Muppets game that very much plays like a product of its time, and while it might not be a masterpiece, it is arguably a forgotten gem.
The console welcomed quite a few licensed projects as well, and a number of these releases decided to adopt the genre popularized by the likes of Super Mario 64 and, yes, Spyro the Dragon.
The PS1 is absolutely overflowing with 3D platformers that have slipped through the cracks of time and nowadays barely qualify as footnotes in gaming's history.