The best gameplay since Half Life 1.
-great soundtrack that stands out
-better balance of puzzle solving and shooting compared to the last two installments
-same immersive and detailed environment, incredible visual design, and great voice acting
-the addition of both rural and urban environments is refreshing, compared to the constant city surroundings in Episode One
-rural forest environments are expansive and beautiful
-a couple new weapons (e.g. double fire shotgun, Magnusson "sticky" bombs)
-final boss battles are hectic and action packed, yet satisfying when over
-decent length for an "episode"
-a lot more plot development compared to the last two installments
Bad:
-Alyx's dramatic reactions are sometimes corny or annoying
Overall:
Simply stated, Episode Two offers the best Half Life gameplay since the original installment more than a decade ago. I felt Half Life 2's gameplay (as well as Episode One's) became a bit boring as I played on because it was focused too much on shooting and not enough on puzzles. Episode Two finally balances these as well as the original Half Life did. This, combined with Half Life 2's incredible Source engine, offers an amazing package. Episode Two also advances a bit more on the Half Life plot, which Half Life 2 and Episode One lacked. Although there are still many unanswered questions, at least some things are starting to become a bit clearer. No matter what, you should definitely play through Episode Two whether you enjoyed every Half Life to date, or found the last couple installments a bit boring, because this one sure does deliver.