If you enjoyed HL2, why don't you have this already? This one episode can put most full-retail FPS games to shame.

User Rating: 9.5 | Half-Life 2: Episode Two PC
Wow, what can I say. I completed episode 1 quite some time ago and I felt it was a slight disappointment to HL2 standards. Episode 2 however has completely reassured me of excellence from Valve once again. Obviously, this is episodic and so don't go expecting a completely new game. What has been done however, is inject variety into the now familiar settings; the underground caves feel treacherous, outdoor areas feel open and the set-pieces focusing on defence are done superbly. The game looks slightly better than episode 1 and the sound design is just around the same. The game's pacing is excellent as usual with some emotionality injected in for good measure – most of that is borne out of convincing animation and voice-acting of the main characters. Expect the usual puzzles from the previous games, but add in a buggy with a new weapon and a magnificent set-piece – and you'll have one of the most amazing 'battles' in a FPS, ever. Needless to say, this is a must-buy game. If you enjoyed HL2 and episode 1, why don't you have this already?