I though I had this figured out already but once you finally get something done you run against another problem.
What's the difficulty exactly? It looks okay to me, though it's a bit unclear what's going on with the wall at the south end of the fire pit room. Has it collapsed into a pile of dirt strewn across the floor? The two just sort of fade into one another.

The room is still dark. What if they're carrying their own light source, as they're likely to do?
When I first started playing RPGs, I spent ages scouring racks of minis looking for THE perfect mini for a character I wanted to play. The character was going to be a male dwarf ranger dual-wielding axes, with an emphasis on stealth and scouting, so I wanted something that looked sneaky. I eventually found the perfect mini for this PC. Sure, he's carrying a dagger rather than an axe, but he's got axes on his belt, and everything else was just right. So I bought it and got it painted up just like I wanted.

And you know what? After playing him for a while, he wound up as the primary melee type for the party and REALLY needed a better AC, so I ditched the off-hand axe in favor of retooling him to use an axe-and-shield combo. Also, the whole stealth thing turned out to be impractical in play most of the time. Horror, the mini no longer matched at all! But I kept using it anyway, and it didn't bother me. Having the exact details of the prop match the current state of game play wasn't as important as I'd thought.

I think the same applies to battle maps. The art represents the initial state of the game world. If it changes, that's okay. People will just have to use their imaginations.