Pretty nice.
ART:
If you find the preview images appealing, you know what you're getting into.
I appreciate that there are so many costumes, considering that each and every variation is available in every sex scene.
If I have any criticisms about the art style, I think I have two nitpicks.
One, the girl's body isn't always consistent. Apparently she has D cup breasts and decently muscular arms when in doggy position, even though in most poses she looks like a B or so and is more slender. But she looks good either way so it's not a big deal.
Two, this is a ryona game so all sex is forced, but she doesn't look like she's adequately restrained. It's just normal sex poses and only dialogue and narration implies that it's rape. That doesn't bother me too much as the only way I get off on rape fantasy is when the victim enjoys it, and it makes sense when she's in the Lusty state, but if you want bondage poses you may be disappointed.
Again, these are nitpicks. The art is in all cases good enough to get off on.
GAMEPLAY:
It's a standard RPGM ryona game with a real-time combat mod, but it's one of the smoothest I've seen.
There's no level grind worth speaking of, although gaining more costumes and money does make the game easier because outfits act as hitpoints and the super-cheap Miracle Pills completely reset the corruption that eventually causes a Game Over. But you don't have to worry about weapons and spells and stat optimization, etc. which is good for a game this length.
My main criticism would be that it's too easy, but that may just be my legitimate gamer coming out. For a knockdown-focused ryona game, you may want it to be easy so that you only get 'raped' by the monsters you like.
My most personal gripe with the gameplay is that even though the sex scene narration tells you that Youmu has been impregnated, every time, there isn't an actual pregnancy mechanic. No swollen belly, no birthing scenes (apart from maybe getting a Game Over but I never did. Again, super easy.) until you actually beat the game and get the free sex room, and even those birthing scenes only apply to half the monsters. Now, a game doesn't need to have full pregnancy simulation to satisfy me, (see my other reviews - there are plenty of games I gave 5-star reviews that don't have preg sim, and some less than 5-star that do) but it's pretty frustrating when it dangles the idea in front of my face and then doesn't quite deliver.
I imagine those with a watersports fetish would also be disappointed. There are toilets around the dungeon that Youmu can piss in, but it's the same scene every time and as far as I can tell there's no gameplay effect relating to urine levels or anything.
STORY:
Half of it isn't translated, but that's not a big deal. The start and end are translated at least so you know the most important parts. There's nothing too offensive going on here as far as I can tell.
Once again I am amazed that a Touhou Project porn parody doesn't require any knowledge of Touhou Project proper in order to enjoy. What is it about that franchise that lends itself so well to Hentai?
CONCLUSION:
It's a competent little game that's worth the time to play - it probably took about as long to write this review as to actually play the game. I'll let you decide whether or not it's worth the disk space to keep.