This game is a first-person shooter on rails--the path is primarily linear (with a few spots where you can choose to go left or right), and gameplay was conducted through a cool-looking light gun which was an integral yet mobile part of the arcade cabinet, akin to Operation Wolf (also from Taito), Steel Gunner (Namco), and many of the others of this era and genre.
However, what really distinguished this game for me, even as an 11-year-old non-academic, was the graphical environmental storytelling. What I mean by that is, despite the sparse textual narrative cutscene which takes place between levels, I found that the majority of the narrative I was experiencing was the result of looking at all the crazy alien and space stuff happening in the levels themselves and ruminating on what those game spaces actually inferred about the world of Space Gun. In other words, instead of being told the story, we are thrown right into a world of alien horror, bereft of direct explanation, in which the player has the opportunity to speculate fruitfully on what that story could potentially be (and hopefully this behavior was an intended design consideration, but it can be difficult to know or confirm these things).
As a matter of topic and genre, Space Gun seems to have evidently been influenced by films like Alien/Aliens, as the player must shoot their way through waves of aliens and save any humans who remain alive aboard the infested spaceships/stations (not unlike Sega's 1987 classic "Alien Syndrome"). That in and of itself can already go a great length towards putting the player in the right genre/world template, especially if that player is already contextually aware of what constitutes an alien-infestation-sci-fi-action-horror experience. So, having already activated all the right moods, Space Gun's level background graphics and character design take it a bit further to stoke the imaginative fires.
At one point there is a boss fight (video:13:44 mark) involving some extremely grotesque creatures in what appears to be a chapel on a space station. The fact that you have been saving cocooned prisoners with increasing frequency on approach to this chapel and boss only conflates the horrific possibilities of what this supposedly sacred place has been literally mutated into. Also, the fact that there is a chapel on this space station at all indicates a lot of things:
-Is the governing body who built the space station not observing the separation of Church and State?
-Is that governing body primarily Christian (as the design of the chapel would suggest)?
-Why did the people of this universe feel the need to erect a chapel on the space station?
And to be honest, these weren’t questions I had now as an academic, but rather the thoughts I had as a kid, trying hard to shoot at the alien monster boss and not at the chapel in the background.
You see, when I was 11 years old, I was still going to church with my Roman Catholic family every Sunday, and also enrolled at the local Catholic private school, so the idea of shooting the front of the church was hardwired as abhorrent in me already. Furthermore, the end of Space Gun (video: 19:55 mark) features a clever mechanic, wherein you must clear the escape shuttle of remaining aliens (and of course, all the aliens on the shuttle are the hardest monsters in the game to that point), and if you should miss the monsters, your stray shot WILL inflict damage on the background, which happens to be the control panels for the shuttle. In other words, your inaccuracy with the gun counts negatively towards the end goal as opposed to simply being a mistake one can recover from. I can’t tell you how many lives and quarters my brother Brandon and I spend on that last level as we tried desperately to 1) kill the toughest aliens in the game, 2) NOT hit the background, and 3) not get clawed/spit at/eaten by the aliens.
And then there’s the part about 40% of the way through the game (video: 8:47 mark) where you start having to fight off an alien space saucer fleet with just your machine gun (and it works, somehow). This scene is extremely reminiscent of the film Close Encounters of the Third Kind, and it got me wondering, as a kid, why these mindless space monsters have control over an apparently technologically advanced space saucer fleet. Either the beast-monster aliens were in cahoots with the space saucer tech aliens, or the space saucer aliens were using the beasts-monsters as footsoldiers, or they were one in the same. In any case, none of the above possibilities is confirmable via the actual gameplay, and the lack of closure on this imaginary meandering is something I personally find more terrifying and rife with story possibility than if Space Gun gave us a definitive answer (ie. “midichlorians”).
And I find the same phenomenon to be true of the whole Chapel thing. Why is it there? What does it mean? The game won’t tell us, and in intentionally withholding that explanation, we are left to our own frenzied, alien-fearing imaginations. And that is likely why I even give a crap about Space Gun today, a whole 24 years later.