Freeman is back ! Awesome AI, Enriched storyline, and Graphics that make the most hardened player jump.
Enemies are smart and the landscape helps and hinders progress depending on the battles being waged. The "1984" big brother element is defined by the ever present Combine soldiers. Although they are human, the feeling the game produces is one of hate towards the combine martial law society and in turn the combine themselves.
HL2 also brings in the expected alien/alternate dimension beings. What is not expected is how different the appearance and intelligence factor is for the creatures. Lastly the weapons rock , especially the gravity gun....what is a gravity gun? Get the game and you know how fun it is to pick up paint cans and shoot them at your enemy.