Notch released a bunch of small browser games back in the day and a lot of these are lost media because Notch moment. A full list of these can be found on this webpage: https://theintraclinic.com/archive/
Currently lost Notch games known to have been actually released include:
Legend of the Chambered (2001)
Droj
Dachon B
Stark
Wrath of Magranon
Pixler
Breaking the Tower (prototype version)
Eye of the Onlooker II - The Legend of Tinymoon
Jack Guzi
City
Anttack
Sunshine Bubbles
CatRace
15m
There may also be others that have been overlooked.