Very rough video instructions are now available on my YouTube channel.
Currently, there are seven videos in all. The first couple deal with prep work that needs to be done, like soldering wires to motors, pins to the battery holder, etc.
The remaining videos demonstrate robot assembly and electronics hookup.
Following along with the videos will take much longer than 20 minutes. A 2020 Bot build could come closer to 20 minutes if this was done in a classroom setting where the instructor could handle questions on the fly. In the video I took my time to make sure instructions were clear.
A PDF template for the 2020 Bot can be found here.
Source code for the 2020 Bot can be found on GitHub.