An old favourite, the headcrab's victim, the zombie, makes his return. In addition to the mandatory model update, the zombie in HL2 now holds and swings his hands in a slightly different manor. It looks like there will also be a few more variations to the zombie's clothes to keep things interesting, if you aren't scared away by those blood curdling screams.

Headcrab

Yep, it's still a headcrab. The basic model and skin don't seem to have changed much, though it seems the HL2 headcrabs have their 'mouths' open a bit more than in HL1. I can also tell you that the animation for the jump has varied slightly; in HL2 the headcrab seems to have its front 'arms' up for the duration of the jump, while in HL1 it only flicked them up as it was falling. Also, we have seen and heard that there are now different types of the little critters in HL2, though we are yet to see what the variation will be, apart from colour.

Characters
Note: The comparison images of Eli Vance and the G-Man come courtesy of some Valve promotional shots.
 
Eli Vance

Making his debut in the original as one of the three default scientist skins, Eli Vance is now looking better than ever. Taking full use of HL2's ground-breaking character and facial animation systems, Eli, now dressed in more casual clothes, seems to have grown a beard and lost some of his hair. I guess a resonance cascade will do that to you.

G-Man

Mysterious as ever, G-Man in HL2 has also been heavily updated. Whole polygons are dedicated to his collar and tie, and his face no longer looks like an angry paper bag. As seen in the Psyche bink and E3 demonstrations, the facial animations of the characters in HL2 are quite disturbingly accurate to real life. Gotta love that suit.

Gordon Freeman

While we don't have Gordon's in-game model for HL2, we can see the changes in concept art. The orange on Gordon's suit has been reduced quite a bit and is no longer seen on his gloves, which supports the new look of the hands in the weapon models. He also has slightly different glasses, though I doubt that will change the gameplay much.

Barney Calhoun

Everyone's favourite security guard is back. Rising from generic ally to a recognised character in Half-Life: Blue Shift, Barney is to help Gordon in his fight against the Combine. He's dropped the security guard outfit in favour of what might be a stolen Combine uniform. And like Eli, he's received a major graphical facelift to match his new status.

Other
 
Decals

Those of you who have access to the Counter-Strike: Source Beta will know that the new blood decals in Source are really quite good. A far cry from the random splotches of HL1, blood in HL2 spreads over surfaces from angle they were thrown at, and creates interesting patterns. There always seems to be a hand in there though.
 
 
Water

Probably the biggest improvement can be seen in the water. The original's water was a semi-transparent moving texture which kind of resembled a blue spider-web. At the time, it passed quite well for H2O but has aged quickly. Thankfully, HL2 is employing the full range of reflective and refractive shader effects this time around — along with proper splashing and physics effects (though stopping short of physically simulated fluid).

Continue on to see how Gordon's arsenal has changed.

Weapons
 
Crowbar

What could have possibly been improved with good ol' rusty? Well, as can be seen in the recent Ravenholm bink, the HL2 crowbar appears to have a reflective coating and is now, what Valve have called, a 'real world object', so it reacts with objects more realistically. As with many of the HL2 weapons, the crowbar is also held on a slightly different angle. Whatever the changes, it still seems to have the same box-destroying headcrab-slaying effect.

Magnum

The classic six-shooter makes its return, now with added polygons. The magnum remains sleek and shiny, sure to dazzle your enemies with its chrome covering. While we haven't seen the magnum hit much in the binks, it is fairly safe to assume that it is still the powerful and accurate beast it was in the original.


Pistol

Here you can see Gordon's trusty 9mm Glock has been upgraded to a 9mm USP Match for his return, but the real purpose of this screenshot is to take a look at Gordon's hand. We know that we are still in the Hazardous Environment Suit (HEV), yet the glove and arm do look remarkably different. The orange has been removed from the glove and suit and has been replaced by grey, and a couple of times when his arm bobs you can see skin. Maybe you have been given a new suit.

Rocket Launcher

The general style of the rocket launcher has been retained from the original, and you can fire multiple rockets without have to reload. Still a formidable weapon, in the binks we can see that it takes two hits from this thing to take down a combine gunship, and it is still unknown whether these things have much effect on striders at all. There is still a laser-guided homing system built in — just keep that red dot on the target and it will be a smouldering wreckage in no time.

Shotgun

Slimmed down a little from the original, the shotgun in HL2 seems to have the same devastating effect on enemies as its HL1 counterpart. As seen best in the recent Coast bink, a single shot from this guy will send ant lions gibbing all over the place. Edit: Indeed, it still fires double-shots with the secondary fire (as seen in the Coastline clip).

SMG

Though the HL2 (HK MP7A1) SMG is of a different model to its HL1 equivalent (MP-5), the two still serve the same function. Alternate fire remains the same with an "on contact" grenade launcher. Unlike the original, however, the MP7 does have a small zoom function, handy for those mid-distance contacts.
 
 
It's easy to see just how far Half-Life (and graphics in general) have come in the last six years. And only good things can come of characters that actually have fingers.