If you hate the "America kills all" game try Red Orchestra it's different from COD and all the other shooters.
But if you want more wacky... Fallout 3 and New Vegas: Spike shooting gun and grenade launching machine gun anyone? Perhaps Rage as well, the engine is meant to be good too

FPS tend to get ignored in the Indie market as they try to find forgotten genres and underused ones and due to COD and Halo, FPS is not one of them.

Yes it does. I think cel-shading scales better to higher resolutions once you get more powerful hardware too. I also love the classic 2.5d look and have no complaints about it either.

The only style I'm tired of is the overly brown devoid of a range of colors look.

I'd like to add another vote to destructible environments too if they are possible.

The first level is set in a metroplex futuristic city. its outdoor a walkway between skyscrapers, we also have transitions between builldings in some levels so you can catch some fresh air, Episode 2 (wich will be developed once 1 sells enough) is a space episode wich uses anti gravity and has portal / prey like puzzles wich has some outdoor elements as far as im aware.

It is our intention to keep the levels fresh and add a new element evry 2 levels. for example

level 1 introduces you to moving platforms.. level 2 and 3 introduceyou to hazardous pits. level 4 and 5 add conveyor belts. crushing walls and ceilings and so on. we also have a lot of pattern based mini bosses to keep it fresh :)

. but we have no such things planned as forests or any open areas. Part of this has to do with the fact that we aimed for a classic doom feel wich is made mostly out of straight shapes and wich helpes keeps the game easy to mod and low poly so its easy to run.

if we where to create a forest level for example it would look too flat and bland

Interesting. I can understand not having something like a sandbox-y area, but to me there's something "majestic" about, like, the use of Skyboxes for an open area. (The "fresh air" and realizing that even though you're running through closed areas, there's a much bigger world out there - these are obviously just emotions, though.)

Nevertheless, keep up the good work. :) Maybe eventually I'll try my hand at creating an "old-school" FPS in the style of Serious Sam (the feel of big open areas, even though there's much linearity) mixed with Blood 2 (linear in the city).

Tell us when it's near done :)