Chronos Twins

The writer and lecturer John Vorhaus recommends that you use something called the 'rule of ten' when trying to come up with a fresh idea. Essentially, this means that if you want to create something – from a film to a business to a book to a game – you should write down ten ideas instead of one, because for every one idea that bears fruit in the world there are nine duffers screwed up on the floor.

Although its opening moments suggest otherwise, Chronos Twins is as much an idea as it is a game. Set in two periods of time simultaneously, using the DS's dual screens to depict this mind-bending paradox, it's both one of the most conventional and the most bizarre concepts of the year, so familiar and yet so audaciously different from any other platformer that it must have been brainstormed on dangerous booze.

The question is, should this idea have made it to fruition, or should it have been left on the floor?

Let's start with first impressions. Chronos Twins is a side-scrolling arcade shooter from the Mega Man mould, a manga-style romp in which you run along the ground, jump over hazards, and shoot baddies.

The game begins with a long and sloppily translated cut-scene through which you learn that a creature called Twime has driven your species from the planet Skyla. You belong to a resistance movement whose aim is to oust this usurper and reclaim the stolen territory.

Off you go, then. After wading your way through a short opening level where you get to grips with your narrow repertoire of jumping (Y or A), shooting (X) and crouching (down on the D-pad), you encounter Twime. Moments later, the top screen flickers to life and you learn that, somehow, Twime is occupying two times at once, and you can't therefore beat him.

So you join him. The top screen of your DS comes to depict you in the present, and the bottom depicts you in the past, with X firing your gun in the former and B in the latter.

It's an odd concept, and it'll take you by surprise at first. If an obstacle appears in one screen while you're watching the other, you'll see your avatar collide with an invisible barrier, stunned, one energy bar poorer. Because you're in two times at once, what affects you in one affects you in both.

This both helps and hinders. For instance, as long as there's solid ground in one of the screens you can walk safely in both, even if on the other screen there's nothing beneath your feet but air and bubbling lava.

Soon after you begin, your allies at rebel HQ also give you the ability to freeze one screen at a time by holding L shoulder and pressing either up or down. The immense relief that these moments of mono-chronological movement bring is short-lived, however, as you're generally only entitled to freeze a screen to carry out some puzzle-based task, such as moving a barrel into the path of a laser beam or pushing a crate where your counterpart can jump on it.

Different enemies exist in each time, so it's necessary to shoot them separately, and some of Chronos Twins's best moments occur when you're coordinating fights on both screens.

However, things are rarely that simple: laser bolts drift across one screen while you're trying to time a jump or fend off a baddie in the other; frantic escapes are brought to a grisly end as you run headlong into an invisible wall; you deftly evade a frying pan in the past only to blunder into a fire in the present.

Even in a single screen, Chronos Twins would have been tough, but across two it's plain frustrating. The problem is, even if you make it through the whole game, there's no prospect of barrelling smoothly through it. The only way to succeed is by circumspection and, more often than not, trial and error.

Chronos Twins's premise is ingenious and daring, so we're not ready to condemn the idea to the floor just yet. It may come to fruition in a more lenient, balanced game, but we have our doubts.

We tried several ways of getting used to the dual screens, like gazing at a point ... Multi-tasking is a feature of many games, but it's rare for the progress of two parallel ... somewhere between the screens and doing it all peripherally, or creeping along a couple of ... tasks to be firmly shackled to one another. While we welcome the innovation, the ... steps at a time to avoid disaster, or simply memorising the levels. While it gets easier, we sense ... distraction that each screen imposes on the other is often just annoying ... that parallel action is always going to be a struggle.

See what we mean?