With a name like "gladiator" I was hoping for something Roman and rough. This is, as you admit, very gimmicky. (just icky?)
Let's talk first about texturing. Recurrent textures are good, but just bathing everything in two or three with the discretion of a walrus is not recurrence, it's an abhorrence. Take a good long look at how the maps in the initial map selection tab look. Try and emulate the style and methodology of those maps.
Next let's talk about sizes. Most of the really good Sauer maps are small, with a very good reason. Everything in this maps feels like it was made one grid size too large: when I first loaded the map I thought I had found a weird bug. But no, you just made everything too large. Push things together, make the corridors *just* big enough to jump and strafe in, and make defensive walls come up to your elbows, not your forehead.
Now let's talk about lighting. As MeatR0me pointed out, even from the screenshot it looks bad. And that doesn't even touch the corridors below. Place lights in logical places with lowish values: no 255ers randomly placed under a staircase.
Moving on, let's talk about extraneous mappage. Outside the confines of the map is a layer of lava over a bunch of empty space. Seeing as the player can't even see either of these, much less get to them, I strongly recommend filling them in with cubes. It's odd that I'm mentioning this extra detail, because inside of the map proper, there is an alarming lack of detail. Sauer can support a tremendous amount of detail even on a weak machine: sport it!
So yeah, back to the basics. I know I'm going to sound harsh, but this map desperately needs help.