Hi, I just bought 3 Thumby's (Thumbies?). I have put all the software I want on the first 2 proceeded to give both a standard update and a MicroPython update. I add the games to the 3rd one, start the MicroPython update, and it freezes at 85% for 30 minutes. Nothing was responding, so I disconnected the Thumby and tried turning it off and back on. The screen is staying pitch black. Could anyone help me fix or reset it?

You can try manually updating it by following the directions here https://thumby.us/FAQ/ in the last bullet point under "Why is my Thumby not connecting to the Web Code Editor?"

To make it easier, follow the steps in the image attached to my comment. Here's the link for the firmware image from those steps: https://github.com/TinyCircuits/TinyCircuits-Thumby-Code-Editor/raw/master/ThumbyFirmware.uf2