This is The Mama Luigi Project, a year-long effort to bring together over 200 artists so that they could completely reanimate one of the most famous episodes of the Super Mario World TV series: Mama Luigi.
255 scenes had to be done, with almost every single one of them featuring a different art and animation style. It’s crazy to watch.
If you see any sections that really take your fancy there’s a full list of credits here. The project was organised by Andrew Dickman from Electronic Heroes.