These are great. They must be abusing note velocity for the "art" sections, right? The melodic parts are obviously being played much more loudly (velocity in MIDI terms) than the beautiful tapestry-like backgrounds. Although I realise a lot of the crazy stuff is also a valid part of the composition (the big blocks of notes emulating drum beats etc).
Excuse me, was it an F or an F# at end of bar 846?
Both.
Very cool! This reminds me of people trying to play Touhou songs on piano. I think the famous one was “Owen Was Her” (sp?).