Looks really good.

Few suggestions, I think may help.

1. Add a Bevel Effect to the Walls to make them stand out a little.

2. I agree with Steel General, Less the shadows a little, not muc, just a little bit.

3. Apply an inside glow on the floor. This will create a slight shadow effect where the floors and the walls meet.

4. At the bottom of your map, Just above and to the right of the word DEMONWEB, I can see that you use the STRAIGHT PATH tool when drawing your map, and you map the walls a single path. To fix this use the FRACTALISE tools to the Left of the screen TOOLS. Right Click on the button, and choose PATH TO POLY tool. This will 'close' the path to a single POLYGON and join the two edges.

To see some examples of some CC3 made Dungeons look for the SHADOWFELL, THUNDERSPIRE, PYRAMID OF SHADOWS, and TROLLHAUNT maps. These maps all have examples of CC3 produced maps.

Good Luck!