I'm working on a level editor for the game. (see latest picture in the gallery)

This way a level can created just by clicking.
It is also planed to add some type of level generator wizard and a level bundle exporter.

For the Editor:

Try out Mappy, a free tile-level editor.

http://tilemap.co.uk/mappy.php

I use this for RTS Levels.
You can set up a tilebased levelground, and
draw the elements into a gridmatrix picture for
visual editing.

Then you just need to write an import function.
I would suggest to export in the one-dimensional csv format, its not
hard to write a stringimporter for that.
(its just a long list of comma-seperated integer numbers,
wich is easy to import)

Thanx for the link. Neat prog (especially the graphically workenvironment)!
But for my needs (inbuilt generator, run level from editor, integrity check, set golbal settings) I tend to use a self progged editor.

IMO it would have been better if you had used more retro like textures without normalmapping, low-res and without linear filtering...dont u think?

The Editor for Castle WolfenDoom3D now is ready (first version without generators)!
It's already part of the setup you can download (link of the first post)

With the editor you can now make levels more easy than before. Just load levels and change them or create new levels.
Mark a section of the grid and choose the object type you want to set from the list.

You can start/test the design of your level directly from the editor (F5).
If you like to share your levels you can publish them also directly from the editor (F3).

I will add a short tutorial for the editor soon.
I will also add more floor/ceiling textures and skycubes.

[@Hummel] The wall textures are from a free texture base and the most of them are nearly exactly the originals.
I didn't use any shaders on them (and the res is 128x128 or 256x256). But I make up my mind to make the textures/models also open source in a futur version.

The smooth lines of the 3D rendered edges kinda clash a bit with the low-rez textures... perhaps the game should run and render at a lower resolution and scale up?

It's also a bit strange how it takes me standing there and emptying multiple clips into an enemy to kill it, since usually hard difficulty levels are based on number of enemies and not so much the toughness of each enemy. I wouldn't call it a flaw though, just strikes me as a bit odd!

You're right with the balancing of the difficulty levels.
But once again - it's the first shot and had to be finished in time.
There's always space for improvement and especially the balancing of games is a time consuming task.
Thanks for your hint - give me some time.

About the texures and the resolution:
I like it as is - it's a remake of on old game (with old media) processed by a new engine. Once I opened the media to be controlled by the leveldesigner everyone can use the texture/sounds/music he likes to.

Funny, excellent, friend.
The graphics looks good.
I am programming a personal garage quake 2 version.
This is the site

http://www.prodigweb.com/quake/garagequake2.html

Thanx Erick_Castro for your nice words!
Your project look also very good! Is there a demo arround?

You should try out applying Ello's pixelation/mosaic shader from the wiki - it will give the game an even better retro feeling