"IT'S LIKE HAVING THREE DICKS!" roars Salvador, spewing a torrent of bullets from each hand.

This is a rather surprising claim to make, and certainly not the kind of thing you'd say in front of your mother, or while having tea with the Vicar. In the world of Borderlands 2, however, with its alien worms, killer robots and midgets strapped to shields, Salvadore's colourful outburst feels perfectly at home. This is a game where enemies use their dying breath to scream, "If you see my wife, tell her she's a bitch!"

Sal's triple-cock observation crops up while dual wielding, or Gunzerking, as the game puts it; as we all know by now, this is his class power. Is it really like having three dicks? I'm not in a position to answer that, thankfully, but it certainly has a sizeable impact on the way Borderlands plays.

In the past we poured obsessively over weapon stats, eager to find the magic loadout capable of handling anything Pandora might throw our way. Now, with the benefit of having two guns out at the same time, there's less concern about having exactly the right tool for the current job. You don't have to choose between the rapid fire of an SMG and the slow-but-heavy percussion of a revolver, for example: you can use the former to spray your target - perhaps dousing it liberally with acid or some other form of elemental effect - and then use the revolver to land a couple of extra-painful hits on top. Alternatively, you could just use a pair of full-auto machine guns and drench the opposition with Rambo spam.

Three dicks or no, Gunzerking is almost bewilderingly effective. Brick, Salvador's punchy predecessor, had the disadvantage of needing to be close to exercise his murderous talents. You could spec him out to be the ultimate meat-headed tank, but this was offset by the fact you were usually running at Trouble head-first with gleeful abandon. Salvador, on the other hand, can happily sit a distance and mince everything in his immediate vicinity. Lord knows how much damage you could do if four Salvadors were playing at once. The cooldown on your class power seems to be significantly shorter than in the last game too - though that may have been tweaked for the sake of the demo.

2K's first UK hands-on with Borderlands 2 also offered the chance to test out Maya, the new Siren character. Compared to Salvador she's far tougher to use, in the short term at least. Her class power, Phaselock, allows you to isolate a single enemy, levitating them into a fixed position where they can easily be shot at by you and your allies. It's a power that could be fairly useful in the long run, and it can be tweaked so that it creates an area-of-effect explosion when activated. On the other hand, Maya herself seems to be a lot more fragile than her dual-wielding buddy; Phaselock can remove one lone threat from the battlefield, but in Borderlands there's usually a vast mob of monsters and bandits queuing up to bite/shoot/lick your face off.

Where Sal's skill trees seem to focus on tanking, reducing his cooldown, and boosting the effectiveness of weapon combos, many of Maya's options seem to place her in a supporting role. She's the one who gets access to healing bullets - formerly the preserve of Roland, the soldier - while other skills allow you to regenerate the health of the entire team, or to use Phaselock to revive allies when they're bleeding out. In short, she feels like a support-based choice at the moment.

The action itself feels very much like an evolution of the first game. There's the same sense that utter chaos is lying just around the next corner, and more often than not this instinct proves to be well-founded. New classes aside, the most significant change is the fact that foes seem a fair bit smarter, and certainly a lot more diverse in their attacks. The demo offered plenty of chance to deal with the kind of enemy tactics that were outlined in the 2011 gamescom reveal.

An early battle in a hostile shipping yard found the player squaring off against dozens of Handsome Jack's robots, for example, with angular mechs stomping about with the support of several flying repair droids, zipping about in annoying fashion like electronic mosquitoes; if you don't deal with these pests first, they'll undo much of your hard work by patching up their heavily-armoured comrades. Elsewhere the game confronts you with a door that will only open once you've crippled - but not killed - a number of robot foes, allowing you access as reinforcements rush in to aid their wounded comrades. In short, there's a far greater need to be selective in your targeting.

Handsome Jack already seems to be a better-drawn villain than the first game's forgettable bad guys, sneering and taunting the player over the radio at every opportunity. But really, the game still seems at its best when forcing you to deal with massive B-Movie creatures. Robots are all well and good, but they're rarely as much fun to kill as the Threshers - enormous worm-beasties that can tunnel through the ground like the stars from Tremors. Imagine a shark's head mounted on the end of a giant snake, with a few tentacles thrown in for good measure. Now imagine plugging this thing with two weapons at once as your character laughs and babbles obscenities.

For all its tweaks and revisions, Borderlands 2 feels a lot like its predecessor. But for once, that's no bad thing.

Borderlands 2 will be released on September 21 on PC, PS3 and Xbox 360.