D'sparil got me thinking so here are some starter thoughts

1.Style
Adventer FPS liks the old with mabye more RPG elements or a whole new way?
I am leaning on HeXeN 2 like just add more balanceing and add some RPG elements.




2.Setting

New or old?

A mix of HeXeN 1 and HeXeN 2 sound good to me like have the portals linking all the worlds.

2.
Weapons
Now heres where it can get tricky use the old rules or make new...I say MAKE NEW

I would like a more of a  morrowind type weapons lets see if I can explain it..I want alot of weapons (mabye 10 each)for each weapon type,the alt fire for the weapons would be thier powered state kind like useing the BOOK on Heretic or HeXen 2.
And some weapons will have their owen status effects and non ammo needing powers.

Scyth
Sword
Knife
Rod
Staff
Mace/Club
Bow
Crossbow
Gun/Cannon

Ammo... we are goign to need mroe than ammo/magic from Hex/Her games so if we make 5 mana types

White:Light/healing
Blue:Water/Pureity
Green:Earth/wind/Balance
Red:Flame/Evil (evil as in rage,anger,hatered,envy,ect,ect,ect)
Black:Destruction/Chaos

So green would be used for most range weapons besides its earth and air abilties to balance this out prehaps BLACK can be used for guns?



the classes would be


Palidine      
Crusader    
Ranger        
Fighter
Warroir
Thife
Assain

Necromancer
Magician
Mage
Elementalist
Sage


The alinment goes light to dark to light starting with melee and ending with magic...Mmm 7 focusing on melee and 5 focusing on MAgic..Mmm oh well these are just ideas.

Since you are limited to carrying only 9 weapons you might can send soem to safe aeras or towns by useing items...altho I mgiht be flooded with to many ideas...keeping things simple never hurts.

A simpleifed version of this would be each class gets up to 6 weapons each and 2 items they can use like the green potion thing.also each weapon gets 3 attacks 1 normal 1 alternet and 1 Magic book

So soemthign like this

Necromancer

1.Scyth cane

reg alt:basic melee
Upgrade 1
Alt fire :basic melle plus adsorbes alil life from enimes costs some white mana or red..

the book doubles damage and adsorbsion and stops mana drain for a short period of time

Upgrade2 (far into the game)
the cane becomes a full blowen sycth delaing more melee dmage and the alt fire dose more and asorbes more costs alil more to use alt to.

Book mode gives him a dark slash for primery fire draining alil dark mana and alt fire is a red slash that absorbes HP and deals damage to thos close to him

I am running out of steam right now...and I am unsure to where you ant to take the dission so I'll let you reply read your thoughts and add to them and what I have posted to where I can.
Mmm going full RPG might be a bit over the top....Keeping it like Hexen 1 and 2 might be the best way just adding to it maby even a town and a store or 2 try and double the weapons and give some of them upgrades...mmmmmm
anyway I think my classes are to many :P
uhg I keep thinking as I am typeing need to stop for awhile *L*

Level design could be like Hexen normal HUB design levels sprouting out from cental hubs,the abilty to aqruire maps and write down lil notes on them would be good.

Dues ex had a good note keeping system.
I swear these new kids drool over D3s PDA system like its new,System Shock 2 and Dues Ex blow D3's PDA out of the water.....

I am always forgettign thigns so a Quest/Mission keeping loging would be nice to.

you have to admit even tho the classic level design had sudo 3D levels it was better than most of todays level design and with that in mind I'd like levels to be built with alot of secrects and some puzzles.


Dont forget I used the Necromancers Staff Scyth as a exsample or a starting weapon and gave it at least 1 upgrade.

we could give all weapons a "UPgrade" and make it where you can turn the upgrade off in the menu window.

Items could be heal,mana refills,armor potions,speed,flight,jump, as for the Green potion goes
each class gets 2
Like the mage and cleric would share the gas  but they would differ in the 2ndry abilty of the green potion mage would get the hovering homeing mines and the cleric would get Mmmmmm mabye a frezzeing or slow gas? mmmmmmm

I've got a Hexen P&P in play. I refer to it as "hexengame". The website is completely out of date so I won't post the link, but it seems to work well.

Just let me know if your interseted