First off, it's interesting. I'm immediately intrigued by these folks. It's very grip-and-grin, which might be what you're aiming for ("You open the door and see...") but tends to be less interesting. I love how you've given the beholder weight by unbalancing the composition, but he looks kinda crowded behind that lantern. I also love the different-shaped pupils. Poor gnome dude is about to get drooled on. I'd prefer to see these folks doing something, not just standing around, but that's largely a personal preference.
You've got a good start with the light, but have you considered moving the armored guy in front? He'd be even darker, and his shadow would be coming toward the viewer, making him more menacing. It might also make him appear less important than the others, so that might not be such a good thing. Right now, you've got a clear balance of power between all four of them.
The architectural details are good, the shadows are ok, the outfits are meh. One-eyed armored dude is the most interesting, and I think you've got an opportunity with the gnome to jazz things up.
Hope this is helpful.