Real Time Projectiles, Cavity Based Damage, Physics Calculated Terminal Ballistics, Bullet Deformations. The Evolution of the First Person Shooter!
Realistic sim that's very accurate and customizable. No overdramatic decoration getting in the way of straight, well-built gameplay. The fear of ultrarealistic combat is strong here. The hope of survival is in the armor when you're knocked down by an explosion and just barely kill the enemy and take cover.
Very fun mod to play with.
The bad thing is there is an excess of settings(that's not too hard to deal with), confusing button layout making it difficult to get used to, and an oddly set-up spawn/weapon setup screen that I cannot understand and end up spamming right-click. (Also, no players, but that's understandable and at least you have bots)
Other than that, there are plenty of weapons to keep one occupied and having fun, realism and weapon models look very appealing, and, to turn a con around, it can be quite entertaining to get used to this game.