Here are a list of GD levels I will make using your songs:
Demon Duck - Duck Escape
Horizon Of Death - Event Horizon
BiCycles - Cycles (GD Cut)
xRayStep - xStep (GD Cut)
Streams Of Serenity - Serenity
Angels from Hell - Angels
Hellemelons - Elemelons
Back To Hell - Back On Track (GD Cut)
Can't Hold On to Lightness - Can't Let Go (GD Cut)
God Meater: God Mode
After Dry Out - Dry Out
Grimmest Reapers - Reapers
Oh and look out for a DJVI level called DJVI mix where I mix all my level designs from that list in one level. Good Job with this one!
P.S. Quack Quack
Oh, and I have heard this song in GD Story Mode IV by MoldyMacaroniX. (Now known as CreatorMoldy, but on a different GD account)