Space Invaders Extreme 2

Rounds, Chains, Lamps, Features; Roulette, Fever, Bingo and Break. Space Invaders Extreme 2 needs a whole lexicon - a strangely camp one at that - to describe its arcane and multi-faceted scoring system. One of the oldest and simplest shoot-'em-ups in gaming became one of the more complex with the original Xbox Live Arcade, PSP and DS game, and in this DS-only sequel, it gets a little more complex yet.

Taito's iconic pixellated aliens have been enjoying a purple patch these last few years, and it was Extreme that set the standard. Unlike the bold reinvention of the iPhone's Infinity Gene or the bizarre table-turning of WiiWare's Space Invaders Get Even, Extreme took Space Invaders into the 21st century by adding innumerable twists and elaborations to a basically unchanged core. Waves of Invaders creep down the screen from left to right, from right to left, faster the fewer they are, as unhurriedly menacing as ever. Your cannon picks them and passing UFOs off.

The basic gameplay was unmistakeable and faithful, not quite as pure a revival as the brilliant Pac-Man Championship Edition, but just as successful at making a faded icon good as new. A Rez-inspired rhythmic techno makeover spruced up the image, but to be honest, the blocky sprites possess so much retro cool that they hardly needed it - stamped indelibly as they are on pop-culture consciousness (and, thanks to French artist Invader, the street).

A much bigger impact was had by the devious formations, new Invader types, branching stages, ingenious boss battles, and above all by the wealth of score multipliers (chains of enemies shot, items collected and UFOs destroyed) and the combo system. You could enhance your score by shooting rows or columns of Invaders, and Invaders of the same colour and shape in sequences called Features. Features caused cannon power-ups (broad, beam, bomb shots and shield) to drop, and pairs of features triggered special Rounds. These, if cleared, unleashed the ecstatic Fever Time, a firework display of exploding Invaders and rocketing score.

All of this is back in Space Invaders Extreme 2. It's not a radical sequel - in fact, to players of the first, it will be an extremely familiar one. You might question the need for such an incremental update, and those who already own a portable copy of the first will have to make up their own minds if this version warrants a further investment. It is better, though - tailored specifically for the DS, and enjoying an even more sophisticated and absorbing scoring mechanic that nudges it a little closer to being a hybrid of shmup and puzzle game.

The biggest back-of-the-box addition is also the least interesting, however. It's the new Time Attack mode which tallies the total time taken to play through the game's five stages (the third, fourth and fifth stages offer branching difficulty options in the OutRun style) - not counting stage restarts when you lose all your lives. Unbroken, that's actually an uncomfortably long haul for a time attack mode, although as with the normal score attack, you can save and restart between stages. And whilst it does offer an alternative goal to simply maximising your score, it's a far less interesting one that often contradicts or bypasses the best aspects of the game's design. You'll have to ignore most of what makes Extreme 2 great and just blast through it to put good times down.