It's based on Valves Source engine.
And it came out yesterday been playing it for the past 2 hours, really a damn awesome game, it has retail quality.
It's a bit like Counter-Strike mixed with Cyberpunk, Splinter Cell and a lot of tactics.
The devs really did an awesome job, the gameplay is very polished, the map design is amazing and they have put alot of details in it.
One of the major gameplay elements is that every player is able to cloak himself (inspired by Ghost in the Shell) and there are 3 classes, Recon, Assault and Support.
It also features a rank system that unlocks better weapons the better you do until the map changes.
Recon is the fasted class with high mobility and longest cloak, also eqiupped with Nightvision but servilely lacks defense.
As you can guess Assault is a middle thing between Support and Recon. Basic mobility, better defense and equipped with Movementvision.
The Support Class is heavy armored but slow and with very limited cloak, features smoke grenades and Thermalvision.
The Gameplay is a altered variant of Capture the Flag, the flag (called ghost here) lies in the middle of the map and each team must bring it to their respective extraction points. The Ghost carrier is marked for everyone by a beacon and he has only a mere pistol for defense however a tactical advantage. If he equips the Ghost itself he's able to see all enemies on the map.
From what I experienced this game really requires a good bit of tactical cooperation in the team since as a lone wolf you will get taken out pretty fast.
Enough talking, head over to
http://www.neotokyohq.com and give it a try^^