Sitting down with Borderlands 2 for the first time, a small part of me was worried that the game would be too similar to its predecessor. Little I'd seen so far of Gearbox's sequel had suggested that the familiar formula would be undergoing any massive changes or overhauls. Borderlands had its share of issues, but it wasn't exactly broken. And you know what they say about things that aren't broken.

The real improvements in Borderlands 2 are subtle but obvious, seemingly minor changes that first-time players will take for granted. Series veterans will be more than pleased, though.

The game once again takes place on Pandora, and though the players' characters are all new, plenty of original cast members make cameos and play important roles in the sequel's story. Gearbox said they're putting more emphasis on the story, and that was easy to see in the two levels I played during the preview.

The first was set in Pandora Park, a sprawling "wildlife exploitation preserve" with rolling outdoor hills and expansive indoor sections. My co-op partner and I played as Maya (the Siren class) and Salvador (the Gunzerker), respectively. Maya's "Phaselock" power allows her to suspend an enemy in the air for a limited time (longer for smaller enemies), though I found Salvador's skill—"Gunzerking," which lets him wield a weapon in each hand—significantly more useful.

Motes of pollen floated through the air as we traversed the lengthy level. Wildlife (read: cannon fodder) grazed in tall grass and fought among themselves. A planet loomed large in the purple sky, partially eclipsed by some sort of station or craft. Inner facilities housed ferocious animal specimens behind force fields, and it came as no surprise when those fields were deactivated and the feral enemies inside were set loose.

Upon entering the Park, we were contacted by Roland (the first game's Soldier character), who outlined their mission. We were to retrieve an item for one of the series' loudmouthed robotic Claptraps, though to be honest I hardly heard what it was. I'd gotten used to ignoring the first game's story, but Gearbox advised me that players will definitely want to pay attention to Borderlands 2's plot.

Other characters from the original made appearances as well. We met up with Mordecai, the first game's Hunter character, who outlined his plan for rescuing his kidnapped Bloodwing falcon from inside the exploitation preserve. Needless to say, it involved shooting our way in. Patricia Tannis also called with her own mini objective—she wanted us to retrieve ten samples of "slag" from inside the facility. It was standard Borderlands quest fare, although the walls of text from the first game were replaced with voice acting.

Combat feels familiar, but like I said, there are a few improvements that are immediately apparent. No longer will you have to stop after every short skirmish and scrounge for loot on the ground; ammo, health and cash are picked up automatically as you pass over them. This alone kicked the game's pacing up another notch and made it flow better and feel faster. In addition, the guns that I had access to seemed even more varied than what the first game had to offer. Weapons from different manufacturers will now have significantly different looks and feels, and some even featured unique animations. An alien assault rifle sported four flaps that opened up as its clip was exhausted, and one shot gun was discarded instead of reloaded—the empty one exploded while a new one somehow materialized in Maya's hands.

The enemies outside and inside the Park were incredibly diverse, and each enemy type still comes in a Crayola box of sizes, colors and variations. Familiar Skags returned to nip at our heels, though old varieties like Badass Corrosive Skags sported the new ability to infect nearby Skag Pups with their acidic traits. The other opponents we faced were brand new: alien Stalkers of Needle, Lurker, Spring and more attributes hurled spikes at us from far away, teleported around, turned invisible, and lunged over our heads to attack our backs. Loader bots defending the compound with twin spinning helicopter blades, bulldozer facades and firearms, while repair bots soared overhead to heal them before we could finish them off. Fire, Grass and Wormhole Threshers erupted from the ground with tentacles flailing, while human opponents harried us with weapons fire.

Each was susceptible to different ammo types; the Stalkers' bio-electric shields could be shocked away with lightning weapons, while bots' armor was weak to corrosive damage. Unprotected humans and skags were easily scorched to cinders by fire weapons.

About halfway through the level, a character named Handsome Jack got in touch to thank us for infiltrating his facility. Apparently he had been meaning to lure us there and kill us; he was surprised, but not unpleased, that we had shown up of our own accord. His monologue was brief but hilarious, and Gearbox assured us that he'd play an important role in the game.

Things got heated as we pushed further and further into the preserve, and the demo ended just as a house-sized robotic enemy emerged in front of us. I'm sure he was the last line of defense between us and Bloodwing, but apparently we'll have to wait for the full game to find out for sure.

The second level was significantly shorter and not nearly as involved. We infiltrated the Caustic Caverns at the behest of Marcus Kincaid, the first game's jolly weapons dealer, who needed us to retrieve some sensitive materials from its bowels. Inside, spits of land and islands dotted enormous pools of acid, hence the cave's name. The enemies here were less varied, consisting of insectoid Varkids and Volatile Crystaliks. The latter were hulking quadrupeds with a weak point on each leg, though their stomping shockwave attack made those weak points difficult to focus on.

An enormous, blue Crystalik greeted us in the Cavern's main chamber, and its demise gave us access to a chest. Inside was our prize: nudie pics of everyone's favorite sexy ringleader, Mad Moxxi. I have no idea how Marcus learned of the existence of such treasures, or how they ended up in the belly of a gargantuan beast, but Gearbox representatives assured me that all would be revealed eventually. Naturally, Moxxi gave us a call to persuade us to return the risque nudes to her instead. The demo ended before we could decide, though I've got my fingers crossed that a third option—to keep the images for yourself—will be present in the final game.

I didn't need any more convincing that Borderlands 2 is likely to be the exact game that fans want. Everything that made the first game great is staying the same, while every complaint I could think of has been addressed. This is one franchise that isn't about to eliminate split screen, and the sequel will even allow two players on one TV to head online and play co-op. Picking up loot automatically cranks up the pace of each skirmish, weapons and enemies will come in even more flavors, the story will play a larger role, and Gearbox has even promised to treat PC players with the respect they deserve this time around. Everything taken into account, I can't wait to play more Borderlands 2 and open up Pandora's box again this fall.