If there's something the DS isn't short on it's puzzlers. Tetris DS, Meteos and Zoo Keeper would be a great collection on any system, but Nintendo's actionloop (also known as Magnetica and Puzzleloop) offers something a little different. actionloop will be most recognisable as a Zuma clone, but is in fact the game that Zuma modelled itself on. Mitchell created the arcade game Puzz Loop back in 1998, which saw coloured gemstones rolling around a track, with the player needing to remove gemstones by making sequences of three or more of the same colour. It's a simple game mechanic, and one which works well on the DS, even if the game itself doesn't quite join the list of elite puzzlers.
actionloop features numerous game modes, but they each share the same basic rules. A line of gemstones must be cleared, and this line can't reach the end zone or it's game over. Player controlled gemstones appear on a launch pad, which can be shot into the line by flicking the stylus in the desired direction. Stones of the same colour will be attracted to one another, so clearing a set of stones leaving blues on each side will cause the two lines to join, removing those if they make a chain of three or more. That's pretty much all you need to know, but each mode throws in a few twists.
Challenge mode is the first you'll encounter, but it's actually the weakest game mode of the bunch. The goal is to clear chains, with each chain that's removed from the screen increasing your level by one. For every nine levels clear you're given either a Rocket (speeds up movement of gemstones and must be removed quickly) or a Multicolour Bomb (removes all gemstones of one colour), and the end goal is to clear level 99. Things start off well, but a rock hard brick wall seemingly comes from nowhere, elevating the difficulty far too quickly. Puzzle games should of course offer a challenge, but in actionloop this challenge comes far too soon.
Next up is Quest mode, which gives you 60 missions to complete. The goal here is to remove all the gemstones in each mission. The difference here is that the course the gemstones move along varies from mission to mission, and there can be multiple launch pads for gemstones. A Fruit Machine-style power-up generator can also be used by landing gemstones in the corner hole, and these power-ups come in the form of bonus points, bombs or very useful speed control items and can get you out of tight spots if used well.
Checkmate is the final single-player mode in actionloop, and tasks players with clearing all on-screen gemstones by using all the gemstones in reserve. If any gemstones are left in the line or in reserve, or if the line reaches the end point, you lose and must try again. Of all the game modes, I found Checkmate to be the most rewarding, but it does descend into trial and error once you move past what would be considered the medium difficulty stages - unless you have the brain power to think nine steps ahead while keeping tabs on what chains are going to be formed along the way.
A multiplayer versus mode is also available for two players with only a single game card, and it's essentially a battle mode, with your performance determining how many blocker gems you can send over to your opponent's screen. Numerous attack items can also be launched into your opponent's screen, such as a cloud that severely reduces visibility and a black hole that sucks in any gemstones that pass near it. Versus is a nice addition, but the gameplay isn't frantic enough to make it something that you'll keep coming back to.
actionloop is a fun puzzler, but it's not quite good enough to earn a place alongside the likes of Zoo Keeper and Meteos. The difficulty curve isn't so much a curve as it is a sudden vertical wall, and other game modes seem to rely on trial and error more than outright brain power. The inclusion of a DS Rumble Pack (also usable in titles such as Star Fox Command and 42 All-Time Classics) makes actionloop a more attractive buy than the game alone, and the sub £20 price tag doesn't hurt either.