It's looking very nice.

If you want to get really technical about it, the water would go up the grout lines a bit farther than where it stops along the tiles do to absorption and the fact that a grout line is a lower than the tile surface. Very minor detail but true, unless everything is really waterproof which for an indoor space would be unlikely. I'm just pointing out a really small detail so feel free to ignore it.

What is the feel you are going for here? Is it a happy place with the sun shining down that has just been abandoned or are you heading for a darker scarier feel? The reason I ask is because to me the coloring seems fairly..I dunno...friendly maybe?

You could add in some rubble around where the columns are busted up and to show some wall erosion but it depends on how long entropy has been at work.

Maybe I've given you a couple ideas to add in but either way, keep up the good work!