Is it possible to connect to some sort of shell on an MT-3620.
I want to be able to see things like top and system performance.
Currently, you cannot SSH into Azure Sphere. There is an update regarding Azure Sphere generally availability in February 2020. As per this update, preview of Visual Studio Code extension for Azure Sphere will be available for both Windows and Linux.
Reference: Plan for changes coming to the Azure Sphere SDK in next release
Hope this helps.