It is definitely worth it. The AI is a little weird, and the voice acting is lousy, but the overall ambiance of the game is great. Typical Half-Life style FPS with a truly gorgeous engine, if your rig can handle it. The beach at night was really cool too. Plus, its fun to shoot the overhead hanging lights and watch the light patterns and shadows on the walls, and so on. Lots of small details that add to the overall quality. How about fireflys in the jungle at night, or the refraction of your view through the scope of the sniper rifle when you're walking. I'm just waiting for the next multiplayer patch since my system reboots during it for some reason. Single players is fine. (Already running 1.1 patch)
<font color=purple>AMD XP 2500+ @ 3200+/200, A7N8X Dlx, 512mb PC3200 Corsair XMS DDR, ATi 9800Pro, Audigy Platinum, 2/5 TB of storage, TDK 48x CDRW, Lite-On 16x DVD, XP Pro SP1, and more neon than a ghetto sled