I don't know what I've done to earn the beta, but after playing it, I have gathered some date, analyzed it with vectorial data structures, then discarded it and ran into walls:
Sunset Pass, thanks to the colormap, has an amazing feel, and I'd recommend something I saw on a contest map long ago:
You know how you have several pillars, right? (Are they one sided?)
Well, behind them, create a sector that has the same width as the pillar, and as it goes away from the pillar, make it thinner. Then use an FOF to set it to a darker tone.
That scenery trick adds a great deal of feel to the level, and you should try it with some raised sectors and pillars in open areas.
Regarding the textures: The triangle textures, despite being a great idea and original, look offputting while running around the level, kinda confusing/dizzying, if you get what I mean.
While playing robotropolis, I noticed that there was a missing lump with music, but that's what made it so great. There was no other sound than rain pouring down relentlessly, and it gave the level a great feel. You should try turning off the music and see what I mean. Then I kicked in some ERZ while I got to the factory.
My only complaint is that the factory's platforming seems tad too simple and too reliant on the bombs (which are a great obstacle) making it feel a bit tired by the end.
You already know what I think about the custom boss, so I won't waste your time here. ;P
So far, I see a mod with great deals of potential, but it's at an early level so faults are to be expected.
Keep up the good work.
(BTW, there are some HOMs every now and then in SPZ, could it be due to the pillars?)