GO!GO!MANIAC! on Rock Band
Pretty much impossible tier on all instruments, especially vocals. Like whoamg those vocals are damn hard...octave jumps everywhere.
Also, me and my friend will probably get around to authoring Utauyo Miracle and No, Thank You because those songs are absolutely awesome, and if they follow the trend of K-On!!'s OP/ED 1, they'll have the special audio and sheet music to go along with them too.