Very unique style, the textures and lighting are so saturated, and the contrasts are so harsh... I like it!

Normally it looks bad, but you seemed to have balanced it out pretty well.
That being said, I'll agree with some of Egg Head's previous post. Albeit, I realize you probably aren't done with these rooms yet, probably still have a few entities left to place and populate it, but at a quick glance, there's nothing really setting your rooms apart from one another.
You might try:
- Using some variance in segments. This leads to the second point...
- Create a few design guidelines for different types of rooms, such as Great Rooms (major rooms with high ceilings or multi-storied, which have several smaller rooms breaking off from them), Sub Rooms (smaller rooms that have specific purpose, like storage rooms, offices, generator rooms, etc, these would generally only be 1 story for the most part, and be relatively small), and Hallways (well this one is rather obvious...). But when designing these types of rooms, give each of them a different style, or guideline for construction, so players can immediately tell what sort of room they're in.
- Design levels as if they were a real life facility. In real life, you wouldn't find a building that just kind of sprawls out randomly, and only has 1 hall way leading to 1 room which has another hallway... Think about how a normal building is constructed, they're designed to make as much use of the space they have as possible, not leaving "holes" in their structure. Now obviously, you don't want to have to make every single room in say... a hotel, explorable for the player, that'd take way to much time, but where a room should normally be, leave the appropriate space for it, and add a fake door that could be used to go into it (if it existed), this will give the player the illusion that they are in this massive realistic facility, even if they can only explore 7 rooms out of the 35 that should be there.
- Following on the last one, be sure to give each room you make a distinct purpose. Ask yourself, "What would this room be used for if it existed in real life?" Is it a storage room? Then it should be sort of cramped with lots of shelves filled with all sorts of stuff, to immediately convey to the player what it is. Is it a generator or some other utility room? Then there should be some big machinery with pipes leading away from it and a control panel or two near it, and maybe a big red button, who doesn't love big red buttons?!
Note that perhaps not all of these entirely apply to you, and that you might have some of these already covered, but they're guidelines every level designer should follow. (well, unless you're doing something whack like Umbra...)
I hope this helps some, you're doing great mate, and its refreshing to see a unique style.
The voices in my head said I'm normal... o.0