I love the piping. If I were to change the piping, it would be to make the red "strands" running down the "wings" either flush with the grey around it, or moved one block higher, so that it "echoed" the grey, while being above it. In either case, I would prefer to see the red wedges in line with the grey wedges and the red flats in line with the grey flats.
The gatling-looking turrets look great. The glass hallways look great and are a unique design idea. I would recommend one or two non-transparent cross-members across the glass roofs, to indicate strong, supporting structure to support stresses on the glass. The halls themselves have the supports, but the big room ceiling is a big slab-o-glass that looks a bit fragile.
The hallway looks great. I like how the white light bar along the red walls immediately call back to the surrounding white walls. I want to recommend a different color for the ceilings, but black is fine. Maybe simply a dark grey, keeping the fans and thruster decoration. as the lighter color to highlight.
All around the printed name "Poseidon", I would recommend building hidden lighting to the side of the word, to have the lighting hidden from outside the ship, but have the lights directly shine on the word to really let the game's lighting engine highlight it.