For the moment it is being developed for 3DGE (EDGE 1.36) but I probably will be doing a ZDoom version as well.
Spoiler:The weapons are almost done, say for a few tweaks and such. They are as follows
1. Big blade
2. Revolver (primary and secondary attacks)
2. Dual revolvers
3. Winchester rifle (primary and secondary attacks)
4. Sawed-off shotgun (single-barreled)
5. Double-barreled shotgun
6. Sticks o' dynamite (primary and secondary attacks)
*7. Gatling gun (primary and secondary attacks)
8. ? (a BFG replacement)
* the player can not walk around with this weapon selected
Also there will be a few new enemies introduced along with some other surprises.
Coming when it's done.
First public beta: http://www.mediafire.com/?x4uvumumsnl76n1
You will need EDGE 1.36 (3DGE) and you need to load both WADs (in which order should not matter).
Keep in mind that this is far from finished, but I feel it is enough to show off.
Enjoy, any feedback would be appreciated.