This game is weird. Not because of its gameplay, Story, or Scenes. It's the absurd variance in Quality this game has in almost every aspect, that make it so interesting to me.
The games plot is this: The earth has been attacked by Interdimensional invaders before. But peace has reigned for 50 Years.
You are a fairly normal, (totally Adult) popular Highschool Student, with a small circle of good friends, including an Anime-cliche-chidhood friend, and a well-earned reputation for helping people.
At some point, the Invaders come back, and you and your childhood friend are roped into a secret organization fighting them.
The story works. It's nothing exceptional in any way, but there is a fair amount of detail put into it. Terms are explained in a glossary, and the game goes out of its way to explain things nitpicky assholes like me might have problems with.
The big twists of the game are predictable, but (imo) treated as such by the characters who aren't complete dumbasses. There is a certain amount self-awareness there.
The characters are mostly simple and uninteresting, at least the side characters. The main girls are similar, for the most part. But there is that occasional hint of genuine depth put into them.
The combat is by the numbers RPGMaker Stuff, when it comes to mechanics, but there is a large skill tree for each character with obvious thought put into it.
Enemies are RPGMaker Assets for the most part (maybe all), with no Animations to speak of. But your characters combat animation is genuinely good. Custom Animations for late-game abilities that look like they came from a GBA Fire Emblem Game. Really well done.
Yet a certain moment in the Finale that clearly warranted a unique animation instead just shifts the sprite by 90 degrees, which looks really weird.
The game is a grindy mess with insane difficulty spikes if you don't grind, that might just be flat-out impossible. But there is a feature to skip (almost) all dungeon content in NG+, making going for different endings a lot less of a chore.
Outside of Combat, the game offers a Persona-Style Life sim, with classes to attend on a daily cycle, free time with activity points, a quest system, and social ranks to go through. But these classes have no real benefit aside from minor stat boosts, the quests are completely bland, and since you can't actually finish more than one girls' route per playthrough, there is no point to do any events but your chosen girls', and after you're done with them, there is no other use for activity points except for repeating H-Scenes, while they are already viewable in the gallery.
The H-Content is well drawn, animated, and offers decent variety. But that variety is shallow, because each girl has only very few scenes, since there are so many girls to "romance". And that further hurts the Dating Sim Aspect of the Game, since you need to play throught the majority of the game at least 7 times to get all Endings.
I could go on, but you should get my point by now.
Someone put real care into every Aspect of this game. And I think that is commendable. it doesn't excuse it's many flaws, but made we want to continue playing for way longer than the vast majority of H-Games have.
I recommend going through the game the normal way, but if you are short on time, install a save editor and make your characters OP. The immense grind is the games worst issue, and skipping it via cheating may enhance your experience immensely.