Severed Steel is a true masterpiece in the bullet time FPS genre. It also has a roguelike mode if you want to increase your gaming experience indefinitely. It also has a Workshop, but lacks a large number of custom maps.

Right of the bat, amount of options to tweak gameplay and UI is impressiveimmersive.
You can remove or add gameplay mechanics, make things streamlined or have more control over your movement. Don't want guys to ragdoll? Want to go slower? WHY?! but okay, I guess you could. - it's a play how you want game.
UI tweaks give it a whole new vibe, let you chose the precise type of cyberpunk you want.

Freedom to destroy the entire level gets the creative juices flowing. Whether it be confined facilities to skyscrapers - "Screw this door, I'm gonna blow the wall to my right and take this corridor instead! BAJAJA! - Make a tiny hole and kill everyone inside! LMAO! - Climb a skyscraper by kicking it! LOL!" The sort of game that makes you excited to see the aftermath.
Being airborne allows for a full rotation, so yeah, I'm setting my sensitivity way up and you know I'm tweaking. 720-front-flip upside-down no-scope gibbing action, rip bozo.
The fact that you can see your whole drip, and it's incredibly well animated, makes it that much more immersive.

Mercs aren't dumb either, you sit in a spot and they start bashing doors and spraying, jet-pack bro trying to hit you from the back, jump-pack bro leaping up stories chasing you down, drop-kick him and he just might dodge ya.

One issue I have is keeping track of my hp but that's on me since the game has slow-motion. So, I try one hit death setting and not worry about health. Sure enough spending 2+ hours on a level in Rogue-Like mode is just as fun. There's a perfect balance of predictability and varied gameplay.

Base campaign takes about 4 hours. NG+, Rogue-like, Arena modes and mutators are there to keep your mind sinking. Not to mention level editor and Workshop. Infinite replay value question mark.(?)

I'll be honest, I don't even like Teardown. I was not impressed by Max Payne. I liked Fear 1's atmosphere and found the gameplay lackluster. Mirror's Edge doesn't have replay-ability and it's sequel doesn't know how to make what good they have fun. I don't feel anything besides ground shaking watching fireworks.
Severed Steel though, is gasmic. This thing is going on the list.

Perhaps I'm wrong but I feel like Severed Steel never really got the attention it deserved. I do have to admit though that at first I also expected the game not to be my cup of tea but that soon changed.

Severed Steel gave me a bit of a 'Mirror Edge' vibe, I guess the combination of minimalistic environments and parkour. Both games are totally different though. Perhaps, if Mirror Edge had you attacking instead of running away + tons of guns and bullet time....

The campaign in Severed Steel is quite lengthy and just so fun to play through. Besides just killing everyone the levels sometimes get more creative in which you have to trigger some buttons or destroy something. Most of the walls are technically destructible which you could use to take a shortcut.

Most of the fun in Severed Steel lies ofcourse in the gunplay. Shooting and killing your opponents feels amazingly satisfying, especially if you combine them with gliding or jumping. Last but not least, I absolutely loved the OST of this game. Several different electronic genre's can be heard in Severed Steel like; Drum 'n Bass, Trance, IDM etc. all fit in the game perfectly.

After you are done with the main campaign there are other modes for you to enjoy and there is a level editor if you want to get creative.

Overall Severed Steel is a great game, hope there will be a sequel somewhere in the future, perhaps with a bit more story.