Who would have thought that a 2D turn-based shooter with relatively simple graphics and featuring some of the tiniest fighters in video gaming would have turned out to be so enduringly popular?

Whether it's the humour, the squeaky little voices, the ingeniously loony weapons or the inventive landscapes, the battle-weary Worms have become as iconic a favourite as Sonic or Lara Croft. That's not to say that mistakes haven't been made along the way, especially when the developers have strayed into 3D territory.

Thankfully Team 17 has now reverted to form with this second outing on the PSP, following up the rather lacklustre Worms: Open Warfare with a whole raft of new features allied with many of the much-loved aspects of the Worms ‘canon'.

For openers there are six new landscapes including World Wars I and II as well as the Cold War and Pirates, and both foregrounds and backgrounds have a role to play; for instance, the pirate ship of the losing team will sink and the water levels will rise and drown the worms on lower levels.

As for the all-important weapons, there are now 24 in total (11 more than in the previous outing) ranging from old faithfuls like the bazooka, dynamite, the Concrete Donkey and the Holy Hand Grenade to newcomers like the Electromagnet, the Sentry Gun, the Buffalo of Lies and the Bunker Buster.

The Electromagnet is effective at both repelling attacks and initiating missile salvos, Lightning Strike will resurrect dead comrades, while the Buffalo of Lies also has a dual role as a bulldozer to smash everything in its path or as a tunnel burrower to give added protection.

In single player as well as the Campaign mode, there's now an additional Puzzle mode where you have to use brain more than brawn to tackle a set number of foes with a limited amount of weaponry. Worms would be no fun, though, without the chance to take on your friends and online adversaries and thankfully Worms: Open Warfare 2 lets you do both. Ad-hoc mode lets you link two PSPs together, Hot-Seat allows you to simply pass your PSP to others and Infrastructure gives you a full online connection.

Once connected you can either get involved in a Deathmatch, defend Forts and use ninja ropes and jetpacks in a Race across the screen or you can check out statistics and leaderboards to see how well you're doing overall. Maps from old Worms series can be downloaded and there are even customisation tools to create new landscapes, flags, hats and even victory dances when your enemies are finally swept away!

A return to form for Team 17 with a greatly enhanced Worms game for the PSP that has loads of new weapons, game modes and multiplayer possibilities while still preserving the best of the past.