Before we get any stupid comments about "Science" let me tell you a story about double-standards:

To get a better understanding of this, you have to compare Gal*Gun to another game: The Typing of the Dead: Overkill. Why, you may ask. This is like comparing apples and peaches, you may say. And I would tell you, that both games are quite similar to an astonishing high level. Both games are rail shooters, both games are kinda grindy (if you go for achievements), both games don't take themselves seriously and have no qualm about showing this, and both games can be deemed quite offensive depending on your personal attitude and probably where you have been born and lived for the most part of your life.
In Gal*Gun you are constantly chased by female high school students, trying to confess their love to you. Your only chance to defend yourself is to shot them with pheromones bringing them Euphoria (or giving them Double Peace). As this was quite close to how my life actually works I thought why not buying and playing it. Then you have mountains of panty shots and your typical tentacle scene and other obscure scenarios like one of the heroines being stuck in a window. And inbetween you have the banter and talk showing the obvious satire existent in the game. Still most people would instantly understand why someone could find this offensive and deem someone playing this as pervert or what else.
But what about the Typing of the Dead? Why would that be offensive. Well you have your mutants, are constantly shooting and splattering them, some kind of obscure sexuality references, high violence and gore and a fuckton of swearing (although it is all "justified" for one stupid joke at the end).
Strangely enough most people are okay with this form of super brutality without batting an eye, while light sexuality instantly makes you a gruesome, pervert pedophile. Talking about double standards :P On a gameplay site Gal*Gun has actually to offer pretty much. Four to five different main routes (with levels shared between routes and levels specific to certain routes), a bad/normal/true ending to all the routes, different paths for some levels, boss battles, events, a lot of humour, some collectibles and a lot of adorable girls all with their own weak points and voice and characteristics. So if you want to play through every main route at least once you have to do a bit of gaming. And then if the main heroines are not enough you have access to the True love route where you can specifically chase that one girl you want to have with a few specific extra lines at the end. They really did put in effort into those girls. For the achievement hunter there is to do a lot as well. Most of the stuff is rather easy (although three fights can be very annoying if you haven't found the cheap way, which I only discovered ater 4 hours of cursing -_-) and then comes the grind. The last 6 achievements I would say are ultra grind heavy especially the collection of all the pictures and girl's data.
From the technical side they didn't put in to much effort. The port shows and explains the whole time the gamepad controls even if none is linked to your pc (game can be player fine with gamepad, sometimes it is easier and sometimes not, I played after 3-4 hours with keyboard and mouse as aiming is easier), the opening movie is non-existant and for several users there is an annoying crash at the end of level 1-2 (and some minor crashed at other points, 1-2 is the most infuriating however). I don't know how often I played that level just for it to crash at the end. And circumventing doesn't always work or you have to take the sour pill of not understanding some lines which is stupid too. So if you can overcome the technical side (and I swear it does munch away at your patience!) and like some rail shooting action the game can only be recommanded as a light-hearted satire with a lot of heart (and euphoria).

Also, if you only join with no real interest of playing the game I will send you my teleporting ball-kicking Unicorn of Doom.