This was really fun to watch through, they use the karaoke scoring system to determine the winner for each round so it's heavily leaning into who has the best technical singing skill. Though generally all participating singers were amazing, it was worth listening from the first.
My personal fave is Gorilla attempting to sing Kawaikutte Gomen and nailing it well lol
I also recommend watching the archive later alongside Yui's watchalong for the full experience (especially for Gorilla's part)
Really nice to see the event being a great success too (twitter trending and over 30k ccv), props to Rikka for organizing this event