Measures in 6/4, that's a challenge! You succeeded brilliantly. I had to listen to it several times because my ear was getting lost in the groove.
The electric guitar solo sounds great on the 4/4 part.
The weakest part is obviously the last one which seems a bit disconnected from the rest and put there to complete the limitation :)
But the first two parts of your music are really good, especially the rough atmosphere of the 6/4.