For your first game it looks fantastic! My first game... I would kill myself, if I had posted it somewhere.
Entity placement is OK, but the rooms look too empty. I see, you have Model Pack 3. There are tons of planks, barrels, small boxes which you can use, to fill your rooms. Some barrels and boxes in the corners, the planks everywhere on the floor.
The lightmaps are OK, too. Better don't use such big lights. They make the level too light, and many atmosphere is gone. Also it looks a bit unrealistic. I don't think, that a such a small lamp would make such shadows on this distance.

Maybe use many (small) light sources for one lamp.
Best,
TheK