He made a bunch of sub-4K Java games, actually
A great way to waste time is to Google any odd topic that happens to pop into your head and play a game of link tag until you strike pay dirt. My latest excursion led me to Sonic Racer 4K, a Java-based Sonic fan game. But what really caught my attention was the name of the developer: Markus Persson.
You know, the Minecraft guy.
After a little more digging, I discovered an old resume that he still hosts on the Mojang page, even though it's no longer directly linked anywhere on the site. Turns out Notch was a frequent participant in the Java 4K Programming Contest, which tasks entrants to create a Java game with a total file size less than 4K bytes. Sonic Racer 4K was a 2005 submissions, but he also made other 4K fan games, including MEGA4KMAN and Left 4K Dead.
I don't know how much of this is common knowledge, but it's certainly a big surprise to me. I like learning about what folks did before they were famous. As for the games themselves, they are impressive considering the constraints, even if they are kind of poopy. Test them out yourselves!