It's been a whole decade since the excellent PixelJunk Monsters paraded onto the PlayStation 3, and in that time, it's been ported to several different platforms. It's one of the best examples of the tower defence genre, with its addictive strategising, charming visuals, and fiendish level of challenge. Q-Games has finally seen fit to produce a sequel, and it retains the foundations of what made the first game so fun whilst bringing some fresh ideas of its own. Unfortunately, not all of these ideas are good ones.

The structure of PixelJunk Monsters 2 is very similar to that of its predecessor. Playing as Tikiman, it's your job to defend a tribe of Chibis from the relentless march of enemies across a handful of stages in each area. Tikiman is able to replace trees that outline the roads with a variety of towers, which will rain down upon monsters who enter their vicinity. Success comes from keeping the baddies at bay and saving as many Chibis as you can. The core mechanics are very much the same, in other words, but that's no bad thing when the gameplay and straightforward strategy is this compelling.

Towers are split into three types to deal with threats on the ground, in the air, or both. Arrow towers will attack any monsters, but do less damage than the ground-only cannons or the air-only machine guns. There's a use for all three basic weapons, and it's down to you to decide where and when to place them. They require coins to build, a resource that emerges from defeated monsters and occasionally from trees as you brush past them. More advanced towers also require the rarer gems to build, but you'll need to weigh up whether it's best to save your gems for a more powerful new tower or use them to upgrade your existing defence.

The game asks you to make a lot of decisions fairly quickly, as the levels are surprisingly fast paced. There's little time, if any, between waves for you to take a breather, so you'll be constantly running around trying to keep everything ticking along. Cleverly, you can upgrade towers by stopping beside them and allowing Tikiman to dance, but this of course uses up a lot of time. The real time strategy found in PixelJunk Monsters 2, as with the first game, is very easy to understand, but has surprising complexity, making for a game that feels quite casual, but offers plenty of replayability if you want to challenge yourself, or find the best layout for each level.

Anyone who's played the first game will know all this, but some tweaks and additions have been made in an attempt to flesh out the formula. Tikiman now has his very own attack; if you jump over an enemy, sometimes an exclamation mark will appear, and pressing X triggers a shell bash that deals a small amount of damage. Trees might drop fruits as you run through them, and they can come in handy against enemies. For example, the Bomby fruit can be placed in a wave's path, and it'll explode as they walk over it, dealing some extra damage. You can also buy fruits with gems from the Mask Maniac, a totem-like being who can be found in each level. In the main hub, he also sells masks and shells, which you can use to customise your Tikiman.

Unlike the original game, levels don't fit the screen, meaning you have to be even more aware of the layouts of each level, and any potential paths that enemies might take. You can pan the camera around with the right analog stick, but the fact you can't keep an eye on the entire level means it's not as easy to manage your towers. In co-op, this becomes more problematic, because player 2 will warp to player 1 if you wander too far apart, where in the first game you both had access to the entire level at all times. The game also features online co-op for up to four players, and presumably the warping issue isn't present here, but we were unable to test it due to deserted servers.

Another, more obvious, change is to the visuals. PixelJunk Monsters 2 replaces the first game's flat look with a more vibrant colour palette and full 3D environments, and it's rather pleasant. It looks sort of hand-crafted and tactile, and the image quality is very clean. If you like, you can also zoom the camera right in behind Tikiman to see things from his perspective, but we struggled to find a practical use for this. Sadly, the move to 3D, as well as the fact you can't see the whole level at once, makes this a more difficult game to read, and varying topography can mean coins and other items will often bounce out of reach or out of sight.

But the heart of the series is there. That highly replayable, deceptively difficult, satisfying core is very much intact, and fans of the first game will simply be happy that they now have more PixelJunk Monsters to play. It's both casual and frantic, and whether you're playing solo or with friends, the magic just about shines through the frustrations.

Conclusion

PixelJunk Monsters 2 is a brave sequel that attempts to fix something that isn't broken, and has ended up taking away more than it adds. The 3D graphics are gorgeous, but the game is less readable as a result, and maintaining all your towers is more difficult when you can't see them all at once. However, the root of what makes these games special shines through, and when you're slaying enemies in a perfectly executed run, the flaws fade away, and you're left with a delightfully satisfying tower defence title that almost anyone can enjoy.