Halo's development has been a long adventure. Nearly two years have passed since Halo's debut on the Xbox, and in that time, the game has sold more than three million copies. Microsoft, Bungie, and Gearbox are now finally putting the finishing touches on a PC version of Halo. Yesterday we were invited to try out a beta version of Halo for the PC and play a series of capture-the-flag games with representatives from Bungie and Gearbox.

Gearbox has rewritten Halo's graphics engine and shader effects for DirectX 9.

Before we jumped into the multiplayer festivities, Randy Pitchford, president of Gearbox Software, gave us a brief look at some of the single-player levels and an overview of what has changed in the single-player campaign. To put it briefly: not much. Fortunately, we did notice that the menu screens can all be navigated using a mouse with a visible cursor onscreen. This may seem like a very minor point, but many console-to-PC ports lack this simple, yet very convenient, interface feature. It's nice to see the development team giving even small details the proper attention.

Within the game, it's apparent that the missions play out the same as they do on the Xbox, including level design, objectives, and the number of enemies you'll face. Not even the damage you deal out or take has been tweaked. After watching Pitchford play through a couple of the more recognizable levels, like the Silent Cartographer, we were hard-pressed to detect any appreciable differences from the Xbox version, aside from the mouse and keyboard interface and the removal of aiming assistance. Surprisingly, Halo appears to retain much of its challenge despite the transition from the Xbox's dual analog controller to the mouse and keyboard. As Pitchford put it, "Legendary [difficulty] will still kick your ass."

There are, however, very noticeable improvements in Halo's graphics, particularly in the character and vehicle models. The resolution can be turned all the way up to 1600x1200, and the game's textures look much sharper and more defined than they ever did on the Xbox. Pitchford was quick to point out that the graphics have been overhauled to take advantage of DirectX 9.0 features. Specifically, the game's shaders have all been rewritten to conform to pixel shader 2.0 standards. Zooming in close to a grunt, we noted specular-mapping and bump-mapping effects on the grunt's gold-colored armor, giving it a glistening sheen over a very granular surface. Similar effects can be seen on the plating of many vehicles, such as the scorpion tank and the ghost.

Despite the efforts at improving the graphics to take advantage of the latest in PC technology, the team over at Gearbox has been equally careful to make sure the game runs well on lower-end video equipment. Pitchford noted that the development crew has been testing the game on a variety of configurations, down to the level of the GeForce2 MX card, which is much less powerful than the graphics processor found in the Xbox.

All of the PC version's new content is in the multiplayer. Halo for the PC will include two new weapons not found in the Xbox multiplayer modes: the fuel rod cannon and the flamethrower. Players familiar with the Xbox version's single-player campaign will remember the massive covenant hunters armed with the powerful fuel rod cannon. In the PC version, this fearsome gun is available for use in multiplayer action. They fire a long, arcing shot of green plasma, which explodes forcefully on impact, packing enough punch to flip a warthog. The other new weapon is the flamethrower, which we were able to use briefly. Strictly a close-quarters weapon, the flamethrower is most useful against enemies on foot.

The PC version's multiplayer will include additional vehicles.

You'll also be able to use three new vehicles in the multiplayer modes of Halo for the PC. The new vehicles include the banshee (the covenant's flying fighter), a rocket-equipped warthog jeep, and the covenant gun turret. The high-flying banshee is particularly effective against other vehicles, as its ability to dodge and attack from any angle make ground vehicles seem like sitting ducks. The rocket warthog is similar to its cousin, the regular warthog, only instead of having a minigun turret, the rocket warthog sports a rocket launcher in the back, capable of firing off three rockets before it needs to be reloaded. The reload time is lengthy, so if you can make it miss three times, you'll be at a huge advantage against it. The final "vehicle" is the covenant gun turret. As in the single-player game, the gun turrets have a high rate of fire, making them effective for base defense, particularly against vehicles like the banshee.