What you first play Half Life 2 you are surprised at every turn. Its the enviroment, its the feeling that wow, this level looks like that place I drove past on our trip to LA. OMG i can use the gravity to pick up scanners and use em as buzzsaws, OMG the pulse rifle secondary
fire vaporized that
guy, OMG i just dropped that
car on those zombies, killing them instantly, OMG i can roll nades into
gun turret holes, OMG my crossbow bolt pinned the
guy to the wall upside down by his leg, or OMG this blue gravity
gun can pick up enemies and throw them at other enemies. I know I've played ravenholm about 3-4 times just cause its awesome killing zombies with the Gravity
gun.
And look how far Half Life has come, people are still making mods for a 6 year old game. Imagine what they can do with the source engine!? Half Life 2
will last much longer than Halo2 and I bet Microsoft is trying to make Halo 3 as fast as possible so people
don't lose intrest in the Halo series. Whereas Valve
will take it's time because Half Life 2 isn't gonna lose intrest anytime soon.