This is not only one of the best Hololive fan games I've ever played, but its one of the best games on all of itch.io!
Everything about this game is superb, the levels are well designed, the sprite art for the stages, the enemies, everything, looks amazing (I especially like the little details like how the flowers move with the wind on the first stage, or how Flare's hair moves as she runs and jumps) the sound is good and the music, which are remixes in 8-bit style of the different Hololive songs, are amazing. Also the controls are responsive, everything moves the way I intend it to. Truly a top of the line game.
If anything, I am surprised that no Hololive talent has streamed it yet. I've seen Vtubers play this game, but none of Hololive yet.