Really liked this idea, and as a tower defense fan I would be so down to play this!
The initial genre definition of ‘PvP tower defense’ seemed to not be as genre-defining, but the inclusion of drawing your own paths around immovable obstacles seemed very interesting - would have loved to see that explored in more detail.
I really liked the Twitch integration idea, which (if I understood it right) would allow teams of players to fight against each other, each with a streamer or captain as its head. This sounds pretty innovative and would definitely make this genre-defining in my eyes, and potentially make the multiplayer aspect a lot more popular.
The overall design sounded interesting and fun to play, and I appreciated the detail given to describing the phases and potential strategies and edge cases (like the AI completing your path if you don’t finish in time.)
However, the document definitely felt too long to me, and very often repetitive, which made it hard to extract the relevant details without skimming too much. It might have helped to modify the original template a bit to match your game - eliminate the sections which aren’t relevant to your game, and merge the sections that tend to repeat essentially the same information. I also felt that the ‘Genre’ section was mostly empty and could have had a lot of good arguments for why this game defines an all-new genre - information that I would otherwise have had to gather from pockets elsewhere in the doc.
Some more diagrams or references in the doc would have been helpful to visualize the map and the gameplay better - but the art references and moodboards at the end of the document were a nice touch, definitely helped me understand the intended look and feel better.