The bad: You don't see the (wrong) output if you don't get it right the first time, making it hard to work iteratively and having to guess what the question actually intended.
E.g. 'Seven files that start with "Santa"' actually wants file names that start with Santa, after some questions that had you use "grep" to search file contents. Where I actually struggled with what's expected is Day 11.
The ugly: Actually a very nice design.
The MIDI protocol is pretty good for what it is designed for, and you can make it work for actual real networking, but the connections will be clunky, unergonomic, and will be missing useful features that you really want in a networking protocol.