The demo's weapons are all complete. The monsters are mostly complete, and the levels are coming along wonderfully, I'd say at LEAST %50.

Also, about Dim3, try this:
Open editor.
Click cancel when it prompts you to open a map.
Select File>New.
Type the name of your map, and the hight, size .ect
Make the hight about 35, the width and length about 150.
You now have a square room with a light in the middle and a player spot as well.
Click the red arrow on the above toolbar to test your level.
When you're done playing around, quit the engine and then try getting a feel for the segements, and how they work in map creation, try moving around the different pieces and creating new ones. Try making angled floors, (drag vertixes up or down) basically just fool around until you get a basic idea of what you're doing. It's a good idea to make this first level like this, and it looks nice too.

Good luck.