After the formula worked so well in Beast Busters, Ocean's conversion of Taito's Space Gun again uses the same mix of the horror genre and the ever-popular Operation Thunderbolt game-style. Thus, in a scenario straight out of James Cameron's Aliens, the player is left to wander the apparently-empty corridors of a dark base in search of numerous trapped hostages, armed only with a pulse laser and a limited supply of grenades.
Whilst the gameplay offered nothing new, though, the Space Gun coin-op simply oozed atmosphere, and this conversion recreates it perfectly with its ominous heartbeats and eerie squeals following every movement.
Busters veteran, Henry Clark's conversion features all the gruesome explosions and strange creatures that graced the coin-op, along with other new features the machine introduced. For instance, whereas Operation Thunderbolt and its many clones force the player to follow a set route, Space Gun occasionally throws up a choice, with the player allowed to select one of two routes during key sections of the game.
One notable loss from the arcade parent is, unfortunately, inevitable, though. Whereas we're all used to seeing Uzis stuck on to the front of game cabinets, the Space Gun machine housed two futuristic rifles which sported an impressive pump action to load in your many freeze grenades, smart bombs and fireballs. On the Amiga this has given way to the right mouse button which, whilst it is every bit as effective, just isn't the same somehow. However, to give Ocean and Images their due, they have made the game compatible with Trojan's Light Gun, adding to the fun immensely - somewhat surprisingly, it also proves to be very accurate, too.
Having selected a one or two-player game, the game opens with the player moving slowly into the shadowy corridors ahead. As can be expected, this is typical Op Thunderbolt territory, except that the dark secretions the Aliens have left on the walls and the general feeling of glooms that the graphics and sound give, raise the game above even Beast Busters in terms of atmosphere.
With the mouse guiding your cross-hair, the game's many aliens tart to appear from the distance, and pressing the left mouse button sends a stream of laserfire towards them. These nasties range from the expected facehugger clones to a variety of multi-armed reptiles and ant-like creatures. Contact with these saps your already-limited health - represented by a set of red, dripping claw marks across the screen - so they must be shot before getting too close. However, as the game progresses, they get harder to kill and care must be taken not to wound any of the hostages within a level.
Each level winds its way through a separate section of the base, past multi-floored decks - complete with gaping acid holes in the floor - and eventually to the escape shuttle which represents the end of the game. However, should all the hostages within a level be wiped out or your energy and credits fully depleted, your mission will be prematurely ended. Likewise, in the final battle within the shuttle, if too many shots slam into the ship's cockpit, the craft will be rendered unusable and your mission deemed a failure.
Gun's levels scroll smoothly in the four compass directions as you pad through the base, and the graphics change accordingly as you get nearer the heart of the Aliens' lair. Also, blocking your eit to the next area are a series of larger mutants who, in time-honoured fashion, must be shot repeatedly until they eventually explode. Graphically though, these guardians are nothing short of stunning, with huge tentacles creatures dominating the screen or legions of smaller creatures making an appearance - brilliant stuff.
Although there are only a few additions to the tried and tested game-style, at least Space Gun offers fast and uncompromising gameplay. The attention to detail adds a certain edge over others in the genre, with plasti-glass doors shattering, and humans mutating into aliens whilst others scurry across the ceiling. One fault I will levy, though, is that the action doesn't vary a great deal, but the continuous changing of the backdrops (which includes a jeep ride across the planet's surface) and the multitude of new Aliens ensures that it will keep your interest.
I am a major fan of the coin-op, and this is the best conversion anyone could possible have hoped for. Very few details have been lost considering the Amiga's relatively-low specifications compared to the arcade game, and this makes of a solid - if unoriginal - shoot 'em up.