Nostalgic!
Maaaaaaaaan! I used to play this when i was children! When my parents was searching for games and i loved Half-Life, then, they realised that those are FROM Half-Life! And then, they said the game was like Half-Life... Well, nothing like it, BUT ANYWAY! I LOVE THOSE SERIES!!! AND REPLAYING THE FIRST ONE GONNA' BE FREAKIN' AWESOME!!!