The weapons are amazing. The Bullseye we just mentioned is a prime example. It fires like an assault rifle, but if you use its secondary fire, you'll shoot a "tag" that'll stick to enemies. You can then duck behind cover and shoot in any direction, and the bullets will automatically race to hit the tag.
But there's another feature, too - if you hold down the secondary-fire button, you'll be able to tag the ground or an object, and any bullets you fire will swarm around the tag like lethal gnats. Fire another tag into the ground, and they'll follow it; fire it into an enemy - like, maybe, a big, tough enemy - and all those bullets will hit it at once. Granted, it's a little hard to use right when you're under heavy fire, but like a lot of the weapons in this game, we can see it getting easier with practice.
That also applies to the LAARK rocket launcher, which seems designed just to make people talk about how cool it looks. You can use it as a fire-and-forget launcher, but you can also easily direct the rockets by remote control, or just get them to stop and hover indefinitely before switching direction. They're especially useful for laying traps, but their coolest feature is that they can actually be made to fire other, smaller rockets as they fly.
Then there are the Black Ops weapons, human-made blends of human and Chimera technology. The weirdest one we saw was the Sapper, which spewed weird, explosive alien egg sacs that work like mines... well, like globby mines that stick to walls and each other, enabling you to form disturbing structures just by spraying them around creatively. You'll have unlimited ammo for these, too, so their potential is literally endless.
