Masterful counterpoint
The beginning feels a little like Bach's allabreve in D
The mp3 you provided doesn't sound like a real organo pleno and I think it's better that way. Whole piece, which is quite long, played with loud pleno registration can be a little tiring, it's very difficult to play so much of thick texture without it feeling weary for the listener - think of Bach's Fantasia in G major (piece d'orgue), it's not impossible, but difficult. Maybe think about some changes of registrations (like in the middle) to give the listeners moments of less intensity
I really admire your counterpoint skills, keep up your great work and please don't stop composing