Finally, a game that gives us exactly what from an RPG game: Just a sequence of random battles with no real story or connective tissue!
OK, sarcasm aside: I actually quite like this, but I feel like this game really needs to be taken in context. If you were coming in expecting a proper RPG and story, then yes, this is a sore disappointment. And yes, I actually do quite like a proper story and a lot of writing; I like getting into the mind of the main character, getting invested in their story, then feeling the crushing sense of embarrassment and loss as they realise their quest to save the world ends not with the big bad's head on the end of a pike, but down their throat, as they kneel before the villain, bound and naked. Or, y'know, something like that.
That said, actually getting something of that quality is rare. The vast majority of RPGM games are barely shovelware to begin with; Just a vehicle to deliver some basic CG's with a larger price tag than usual. Some do come with some good writing, but they're very infrequent, and even then run the risk of the dreaded Machine Translation. Frankly, if the budget can't stretch to good writing on top of good art (and maybe sound), I'd rather skip as much of it as possible - a lot of mediocre waffling and bland fetch quests won't make things more fun, although they do add to the setting when woven into a good story.
Bearing that in mind, I actually quite like this game, considering it bills itself as exactly what it is; A barebones RPG which basically just focuses on the fights and battle-rape. As far as I can tell, that really all there is to the game, and it's pretty streamlined - you start "searching", and there's a random chance for a treasure chest, trap, or enemy, as you tick the exploration meter up to 100%. The game even has a few different options for playing through - full manual control, auto-battling, or just straight up unlocking the gallery if you want don't really want to play through properly. If you do play through rather than unlocking, enemies appear in the gallery as you encounter them, and all enemies on a level are unlocked on level completion, if you happen to miss one. If you want to see a specific scene in a fight, you can pick that out as a starting point in the second gallery section.
The fights are generally fairly balanced on normal difficulty - certainly challenging at the start, but improving as you buy or find new equipment (all randomized, including the buying), although I did stop fighting through the story myself at the end of the main game's boss because it felt just a bit too hard/grindy to get through. Most fights do feel rather threatening, and there's the constant sense of being close to being overwhelmed, which adds to the mood of the sex scenes. Skills are all cooldown-based and cooldowns carry over between fights, so just spamming the most powerful moves may not be the best plan if an enemy's near-dead already and the boss may be coming up soon.
Without relying on words, the scenes are pretty close to being as good as they can be. The sound effects are pretty standard, and the VA fits the girl's appearance, generally sounding cute and quiet. The clothing's a bit cliche, but I quite like Luna's appearance, being a fan of smaller and cuter looks myself. The sex CG's are all still, but with some morphs and effects at times. Most enemies have scenes that progress as they/you orgasm, but usually still with the same main image - e.g. going from a single tentacle in the pussy, adding one in the ass after one orgasm, one in the mouth after another, and one as a blindfold/extra tentacles to bind after a third orgasm, progressing in seriousness as you get closer to full defeat. Overall, I feel like it works very well towards giving that sense of helplessness and danger that most of these scenes should be aiming for.
I do feel that there's a lot of room for improvement, despite my rating (really it'd be more like a 7 on a more granular series). The most glaring one being that I would rather there was a proper story and writing to accompany the battle rape, and some ending scenes - however, again, if it's a trade-off between "bad writing" and this, I'll take this. There are a lot of scenes with enemies, but they do get a bit repetitive, especially among tentacle-y enemies. I'd really prefer a bit more inventiveness or branching out into different fetishes - bondage/shibari-focused enemies especially could have worked extremely well, and fit the theme of getting more extensively trapped after every orgasm. Also, because scenes are based off of a single CG, they do feel a bit static sometimes, despite the nice progression. I'd maybe have preferred half of the enemy numbers, but with sex scenes that end up with Luna being repositioned as they progress; Say, going from a couple of tentacles having her standing up, to flipping her upside down after a few orgasms, then having her absorbed into a tentacle mass after a few more.
Overall, I'd say the game's pretty good for what it is. If you like battle-rape especially, it's great. Just, y'know, don't go in expecting a deep story or anything. I feel that the devs have put a good effort in balancing the fights, making the scenes, and opening up the game so the player can see what they want to see. There's a lot missing here compared to other games, but it's not for a lack of effort, but more a conscious attempt to streamline.
