Legibility of the System Font
Since two releases the font, which is accessible via MicroPython has changed to 'Comic Neue' as this is an open source typeface and the previous one was not. This is a good choice when it comes to the license, but unfortunately 'Comic Neue' is not easy to read and renders ugly in smaller sizes.
For the next release, I'd therefore suggest to switch to an open source font with better legibility as standard font, such as 'Inconsolata': https://github.com/google/fonts/tree/master/ofl/inconsolata or 'FiraCode': https://github.com/tonsky/FiraCode