There is a lot to say about this game, both good and bad. This game has a lot of design elements that aren't seen any more in other shooter franchises, for better or for worse. Seeing this game's multiplayer years ago during the early days of Counter Strike, I was enthralled by its advanced destruction physics and somewhat detailed gibs. Playing through the single player again recently, I nociced how fresh and different the weapon behaviours were.
The gameplay is fast and brutal, the enemies don't have a lot of health, and they have weapons that can rip you apart in an instant, encouraging players to play either carefully, or agressively. The weapons sound very meaty and are very satisfying to fire. There are also the inclusion of NPCs that react to your actions, either firing at them, pulling your weapon out, or approaching certain NPCs with an injury. In a way, there is a lot to be compared to Half-Life 1 with the fast, brutal encounters, the linearity with some tribute paid to exploration, the interactive NPCs, and the general Sci-Fi theme. What sets it apart though, are the advanced destruction physics which allows you to blow open walls and structures, sometimes revealing secret passages or shortcuts, giving players a feeling of agency.
However, there are plenty of issues that hold this game back, the most noteable of which is the pathfinding AI, which frequently gets enemy NPCs stuck on geometry or simply shut-down, turning them into still statues until you start shooting at them. The stealth sections felt crowbared in as a very flimsy excuse to reset the player inventory for each act, and they are not very compelling or properly implemented as the enemy AI creates scenarios where stealthing through each section are nigh impossible. It is often better to just run through the enemies, as they're too inaccurate to land enough hits on you to kill you, or blow through them, as they provide more than enough supplies when they die. Not only that, the stealth sections are programmed so that you can never fall below 1 health. Another thing is that the weapons that the enemies use during the third act of the game pretty much makes it so that the best way to get through a section would be to save-scum after every encounter, since the snipers can shoot at you through walls with their Rail-Drivers and it's extremely random whether they would hit or not. There's also the weak major boss battles where the only weapon capable of defeating them is the flamethrower, and the ending which throws an arrow guessing game at you at random instead of an epic battle. One more final thing that holds this game back is that, unlike Half Life 1, the graphics and model quality simply didn't age well.
Despite its flaws though, there is a very good game underneath and I feel that had Volition had more time to polish and do QA testing, this game would be able to stand abreast of Half Life 1 as a landmark piece of gaming curios. Do I recommend this game? Definitely! There is a lot to like about this game, and for just $9.99 you can definitely do a worse than play this game. If you decide to pick this game up though, it is imperative that you download and install the Pure Faction 3.0 patch and the Pure Faction 3.0c beta update, as it adds a ton of fixes that improves the experience immensely, like widescreen resolution support and mouse raw input.