It all begins as a straightforward astro-geological survey of an anti-matter planet in the outer reaches of the galaxy. As you make your final approach there is a rumbling below your ship, the ground falls away beneath you, and you tumble into the abyss.
After minutes of grappling with the controls you finally manage to stablise the ship only to find yourself in the first of eight alien caverns.
Blast, from Audiogenic, is based quite unashamedly on the Superior Software classic Thrust. Most of the original elements are there - the small triangular spaceship, the relentless pull of gravity, and the ever-present threat of alien attack.
Unlike the multi-screen, scrolling, backgrounds of Thrust, Blast limits the size of its caverns to a single screen and achieves its complexity by reducing the size of the sprites. The game controls are very similar, allowing ship rotation, thrust and fire. There is no tractor beam because you aren't required to collect any power units.
Not only does Audiogenic provide a facility for fussy players to define their own control keys, it also panders to the needs of those less wealthy BBC Micro gamesters who are asked what type of display you will be using; a monochrome reply results in the program defaulting to a selection of colours more suited to your needs.
The object of the game is to destroy all alien command centres, of which there are three in each cavern. With these out of the way you are free to attempt the next level. Not surprisingly, the aliens aren't going to leave their command centres sitting around for any old Tom, Dick or astro-geologist to blow to pieces.
The alien offence/defence system consists of several categories. Wall-mounted gun emplacements that loose a constant volley of randombly aimed laser blasts, highly mobile, but dumb, catherine wheel devices trundle around the cavern walls, and less mobile, but not so dumb, homing mines gravitate towards you relentlessly.
In addition to the indestructible cavern walls there are rows of little barrier blobs that create temporary obstructions throughout the caverns. The accessibility of some of the command centres is restricted by the physical shape of the cavern itself - nasty little narrow and angled corridors are often the only route to a centre.
On the higher levels the complexity and ferocity of the onslaught increases quite dramatically. Volcanic eruptions belch streams of explosive bubbles across your path. On level four the usually obstructive, but immobile, barrier blobs succumb to the effects of gravity and begin tumbling from the skies.
The leisurely, but thoughtful, approach that has served you so well in the previous levels now have to be abandoned in favour of a less systematic, blast-everything, technique. It is at times like this that you reall appreciate your ship's auto-fire cannon.
You begin the game with three spaceships, each having infinite supplies of fuel and firepower.
Such generosity enables the cautious player to take his or her time to complete each cavern without loss of life. On the other hand the Joe Cool space aces out there are most welcome to try and take out the command centres before the count down timer reaches zero, thereby qualifying for a handsome bonus.
Blast has managed to re-create the physics that worked so well for Thrust. Minute blips of thrust are necessary to maintain the ship's position in space and all sideways drifts have to be compensated for with a brief thrust in the appropriate direction.
When you are expected to fly a ship through tortuously twisting narrow caverns the accuracy of collision detection routines is of paramount importance. There is nothing more frustrating to an ace pilot than to see his ship consumed by flame when he knows for certain that he missed the wall with millimetres to spare.
Blast's routines are perfection. You can fly your ship to within a pixel of an object in complete confidence, knowing that the craft will not spontaneously combust.
The graphics used throughout will never win any prizes for style or originality, but I don't consider this to be a major failing. Blast's main strength is its superb gameplay.
This is a game that responds to the skilful player. With four fingers working in unison the ace pilot can pivot his craft in the narrowest of tunnels while simultaneously blasting mines and command centres.
Within half an hour you can be flinging the ship about at high speed on the lower levels in an attempt to reap the largest possible time bonus. I enjoyed it and I'm sure you will too.