Jane Austen. Tolstoy. Shakespeare. All big names in literature and culture, no-one can argue about their importance or question their position as the creators of extraordinary works.

Deep, the new game from 3D games developers Fishlabs, could – arguably, should – be spoken of in pocket gaming circles and wider in the same manner.

To get straight to the point, we've never encountered a game that's this grand in scale, so expansive in play, boasting such polished production values and brought them all to a bog-standard mobile phone.

We'll deal with the visuals first, and quickly: they're as detailed and eye-wateringly pretty as ever from this developer.

We've come to expect that sort of thing from Fishlabs by now. What makes Deep such an important game is the way that the visuals are merely a warm-up act to a game that's so grown-up, and indicative of a mobile phone game market that's finally come of age.

In Deep, you play a Lone Ranger-esque type on a far-flung planet of the future that's flooded, reducing the planet to a water-covered orb floating through space. Ever resourceful, mankind has dived beneath the waves to live in submerged docking stations that drift in the murk as if it were space.

Making a living as a fisherman, you begin by hunting the local fauna in your one-man submarine, using a harpoon to drag the giant shrimp, nautilus and nameless aquatic creatures back to base.

There's not much of a living in fish (probably the fault of Spanish trawlers) so you branch out into mercenary work, killing pirates, escorting freight convoys and clearing mines, where there's real money to be made.

In any other mobile game, you'd be lead by the hand up this little career ladder, but in Deep you're left to climb as high and as quickly as you want. Or, indeed, to fall off it. Thanks to a nifty system whereby you take jobs and missions from the local docking stations' version of the Job Centre, you can pursue your own agenda.

Deep's gameplay meets the high standards set of it by the structure and presentation, with your little (to begin with) sub zipping around beneath the ocean waves. Thanks to the various temp jobs you take on, you'll soon earn cash to spend on upgrading the weapons, thrusters and shields, before buying an entirely new sub altogether.

Did we say 'shields'? Yes, we did, and they're important for more reasons than being attacked by submersible pirates: at the beginning of the game, with your puny little craft, you're limited to how deep you can dive, due to the increasing pressure, and how close to the surface you can go, due to excessive radiation from the sun.

As a result, you're confined to a belt of ocean between the two and are limited to taking on missions in this belt. It's a great way of breaking up the game, and adds an enormous sense of progression; the more money you earn, the more advanced a craft you can buy and the more dangerous and exciting are the missions you can go on.

Wonderful stuff. There is a 'but,' however. Like most great pioneering works, Deep has its flaws.

Firstly, and not for the usual reason, are the visuals. While your underwater world looks great, it's perhaps a bit too realistic – everything's so dark that you end up having enormous difficulty in seeing many of the objects you need to capture / rescue / destroy until you're right on top of them, making many missions harder than they should be.

Secondly, there's no way to exit a mission once you've begun it. For one reason or another, some missions you sign up to are too difficult to complete with your sub's current configuration. But there's no way to quit the mission, short of dying, in order to take on something easier.

So while Deep is to be applauded for pushing the limits of what a mobile phone game can be, it can be a frustrating experience to play.

The good times outweigh the bad, so don't be dissuaded from getting Deep, if your handset can support it (it looks far better on a big-screen 3G phone than a smaller 2G one, like our test Sony Ericsson w810i).

But if you're after something that's as fun as it is seminal, stick to Fishlab's prior effort, Galaxy on Fire, a game upon which Deep draws heavily.