There’s a little kit called the SMD Challenge which goes down to 0201 components, but uses a big SO8 micro to run it. I came up with the idea of using a 555 timer in a tiny CSP package, decade counter in a little QFN, 0201 LEDs and 01005 passives. The challenge, if you’re willing to accept it, is to only assemble it with a soldering iron!
More info and files available on GitHub
Fred Temperton 