@D.L. Yomegami It looks too clean because your biggest single 'space' is spotless i.e. the central section with the crystals. I'd mess that up a bit.
In addition -
break at least one of those perfect stained glass windows,
if you have enough floor breakthrough to allow a sturdy vine to grow, then I'd remove some of the floor tiles completely and have earth/grass showing through.
Why, if this temple has not been used for a long time, does it have 2 complete sets of lit and new, because not burnt down at all, candles? Plus the torches with whatever fuel they use? If you need lighting, then you also need screen tinting to make the place dark enough to require artificial light.
One neat circle of darkened/dirty floor tiles looks artificial. Either have more, and randomize it, or have none.