I'm digging the progress here.
I think your lighting looks ok, but overall for this being a tomb it feels too bright to me. Try making the scene a little darker, with brighter lights on the pedestals (where flames are in the reference, and have the lights be a little brighter with a quicker falloff. Not sure how tightly you want to stick to reference but maybe you could try playing with the light color. Maybe have a purple or greenish ambiance to the scene. Just an idea, adding color might look cool. Or even have some ground fog to add to the creepiness of the tomb.
The floor texture seems a little too harsh to me. Considering how the tomb is worn, and has erosion on everything, the ground seems a little too new. The ground should probably be at least as worn as everything else, but probably more so. Generally the floor/ground would have the most natural wear and tear since you'll more likely have erosion from people walking on the ground than rubbing the pillars/walls/etc..
Make sure you don't skimp on the details here. The concept has kinds of cool details: The hieroglyphics all over the walls, the little detailed wall pieces near the floor, broken stones, skeletons, cobwebs, sand pouring down from above... This can be a really awesome piece as long as you keep going with it. Good luck!