Your second paragraph is great, and your third paragraph is a nice closer, but the first paragraph is kind've weak, and overall you need to include more details. You spend all your time saying how great it is, but little time explaining WHY its great. Your second paragraph, however, is great in this regard.
Also, your first sentence seems a bit wordy and redundant. Maybe you could say something like "Killzone 2 is the most impressive shooter I have ever played, on any platform."