I took notice of this project, it caught my eye! But truth be told, it'll need alot of polishing before it can be truly grand. The flow and such I can jive with, but things like level design need a serious kick in the romp. Which I'm considering offering my serivces on.
Check out my project: DESPAIR for Heretic - the monster roster for THIS mod though I udnerstand you want to be more expansive, including critters from Heretic, HeXen and beyond. I noticed that your still using a .wad file and NOT a .pk3 file, however, to organize things. Also your gold seems to phase in and out of existence - you might consider a new sprite - Dragon Shards! I use these as armor bonus pickups in my DESPAIR mod but we can change them to be the currency, instead. We can add critters such as Chainmail Ettins, the Saberclaws should all jump, and other differences considered for a more 'concrete' experience. Also, 'Ressurecting the Serpent Riders' has been done to death, BUT - the simple changeover to the SON'S OF D'SPARIL cult resurrecting / summoning some NEW big bad is similar enough but still fresh. We can have the 'Ranger' archetype (the Corvus / Assassin style class), a Blood Knight (utilizing some Demon Eclipse weaponry, + warrior from HeXen), a NecroMage and a Paladin (fighter-cleric). I say - for now at least - ditch ammo altogether and we use a six-color mana system to further tie in Heretic / HeXen into a new world.
As for level detailing... Level 1 seriously needs to start in a village, and the corresponding outdoors area is no doubt the 'overworld' of the mod. The hub format you have here will always go back to this level... much detail needed, and I can help. Please, sample this 5-level mission pack I made for Heretic and you be the judge....
http://www.mediafire.com/download/dhhcf ... Shades.zip