When movie-making supremo Steven Spielberg announced that he was working on a concept for a video game there were mixed reactions. Those of a positive mindset felt that his uncanny knack for set pieces and heart-tugging narrative would produce a big-budget, effects-laden masterpiece. Others felt that here was another creative type jumping on a band-wagon that they really knew little about. A glorified interactive movie was surely all that could be expected, right?

Wrong. On both counts. Completely eschewing any form of narrative and without so much as a nod to cinematic conventions, Boom Blox shows that the great bearded one really has his finger on the gaming pulse.

The objective in Boom Blox is to remove a selection of coloured blocks from the 2D field of play within a limited number of moves. Viewing the action side-on, you have to position a cursor using the thumb-stick and then press '5' to fire a weighted ball at the desired point.

Targeted blocks will react realistically depending on where and how hard they have been hit, pinging off at the appropriate angle and velocity. If they drop off the edge of the screen you score points - 1 point for a blue block, 2 points for a gold block. Score sufficient points to achieve a bronze, silver or gold medal and you'll move onto the next level.

It sounds simple enough, but it won't be long before you realise that the number of turns permitted falls some way short of the number of blocks on screen. To counter this you will be introduced to a wide range of blocks possessing special attributes, which will gradually populate the levels for your use.

Target a bomb block, for example, and the resulting explosion will send any surrounding blocks flying. Contact of any kind with an Arrow Block will send it scooting off in the direction it is pointing, shoving any obstructing blocks out of the way.

With many more of these powered blocks to play with it soon becomes clear that you need to set off a chain reaction of events that will rid the screen of multiple scoring blocks in one turn. Think of it as a sort of free-form domino rally. Only with explosives. And much more fun.

Although a great deal of trial and error is required, it never becomes tiresome. You're only ever a few button presses away from a swift restart, and experimentation is always encouraged.

Because the levels are effectively over in moments once you've figured out how to solve them, it makes Boom Blox not just an excellent game, but an absolutely brilliant mobile game. You can pull your phone out and rattle through a level in less than a minute, making the game eminently playable on even the busiest of commutes or during the briefest of tea breaks.

With increasingly cluttered levels it comes as a relief to find that the visual design is bright, clear and simple. Each of the blocks is distinguishable from the rest at a glance, whilst the backgrounds are commendably unobtrusive. In short, the graphics suit the gameplay, which is just as it should be. This isn't the game to wow your non-gaming friends from a visual standpoint, but hand them your phone and you won't be getting it back in a hurry.

All this praise and we haven't even mentioned the in-built level editor. Once you've exhausted the game's generous helping of pre-made levels, those of a creative nature can try their hand at designing their own. It's a powerful yet intuitive tool which allows you to create levels to more or less the same standard as the existing ones. The only limits are your own levels of imagination and patience.

You can even- where available - upload your fiendish inventions for others in the Boom Blox community to experience, and in turn take theirs for a spin. It's a welcome feature that serves to suggest that Boom Blox will have pride of place on your phone for some time to come.

The excellent level editor goes some way to rectifying the game's only real flaw. With so many elements to introduce to the player, Boom Blox takes a fair while to hit its stride. It's not until the later stages - particularly the fiendish Challenge levels - that developer Iugo really stretches its legs and lets rip with some inspired level design. Until then it can seem a little like a protracted tutorial level.

But we really are being picky here. As a result of this softly-softly approach Boom Blox will be picked up, mastered and loved by anyone with an open mind and a healthy sense of fun. From Mr Spielberg's genius concept to the near faultless execution by Iugo, Boom Blox is a triumph of mobile gaming.