Updated this review after getting further into the game. I'd leave a neutral review if possible, but since I can't, I'll leave a "not recommended" just so anybody looking at that section of the reviews before buying has something more to go off of, as the most detailed negative reviews of this game are all in japanese so far.

TLDR: It's a roguelike with a focus on party building that is relatively fun for about 30-80 hours depending on the player, that drops off hard into tedium, lack of depth and a lot of "!@#$ the player" mechanics later. Your tolerance for bull!#@$ and your love for monster girls will play a heavy factor in whether this game is worth it, but if you're thirsty for a monster girl game that isn't just crappy eroge, this will scratch an itch.

The good:
- Many types of monster girls you can recruit. Most bases are covered, a few aren't.
- Core gameplay is initially engaging and satisfying
- The (free) music choices are excellent.
- Until much later in the game, it isn't too punishing for a roguelike. Fruits of resurrection help a lot.

The bad:
- Whatever you think of the art direction aside, many of the areas are boring to look at and many of the girls look same-y. Some models and animations are very unpolished and janky.
- Each type of monster girl has 4 tiers, each with a sizeable power gap between them and a different color palette. You can't "promote" girls, and while technically you can raise even a tier 1 to be as strong as a tier 4, it would be very time consuming versus finding a tier 4 you like the look of.
- Monster girls have level caps, usually starting at 20-40. Once a girl is close to her cap, you return her to level 1, gaining a VERY small boost to her base stats and increasing her level cap by 10. This works fine for the early game, but in the post game stuff, wellllll... the max cap is 200. Raising it by a mere 10 at a time is just miserable. Especially if you recruit a new girl you want to get to a useable state, depending how far you are into the post-game dungeon, it can be hard to want to go through that grind. It becomes a sh!tty version of the similar system in Disgaea.
- After the first couple of dungeons, we have mandatory* gimmick dungeons. What kind of gimmicks? Nothing interesting, just restrictions. No bringing in items, no bringing in monster girls, no recruiting monster girls. Huh? Who asked for this? The appeal of the game IS the monster girls and accumulating items. Without those it's not a particularly engaging roguelike. *Thankfully you can skip these dungeons to get back to the main game if you choose to, but I don't know why they exist in the first place, especially before post-game.
- There are a LOT of useless items, and a LOT of items that are dangerous to use without knowing what they are. Items beyond the first few dungeons are all unidentified by default, and identifying them every time quickly becomes a chore due to how many are just utterly pointless. You will find yourself stuffing your inventory with dangerous-to-use items to bring in with you just to have them pre-identified so you don't ruin a run with an unid item. Alpha monsters (super powered up minibosses that can spawn on any floor) usually require some kind of prep work to safely deal with, but the items they drop are almost never worth it. I've never had them drop anything better than what I can get from using Magic Keys.
- Base inventory space is incredibly limited, and managing storage pouches is clumsy and cumbersome. I've lost count of how many times I've fumbled going into a pouch to grab an item to hurl, to instead hurl the entire pouch itself, pelting the enemy in their stupid face with my pouch and destroying it in the process.
- There are a lot, a LOT of hazards that can lead to instant death, party member death or item loss, both RNG and non RNG that you need to account for. You will need a lot of inventory space for this, and you will be wasting most of your gear/girl customization on this, too. Most progression in this game is entirely building around mitigating ♥♥♥♥♥♥♥♥. About 95%, compared to 5% of you actually feeling like you're getting stronger. The amount of preparation you will be doing purely for the purpose of not getting scummed out by some bull!@#$ HEAVILY limits your options in almost every area of the gameplay.
- There's also plenty of hazards you can't mitigate or prepare for, including ones you can. What do I mean by that? Those anti-rust and anti-steal symbols you stuck on your gear? Late game monsters will just outright ignore them, they don't work.
- What skills monster girls can learn are heavily restricted. Some girls far outclass others. There is a post-game difficulty setting where enemy monster girls randomly learn different skills every few floors. I don't know if these include skills they can't regularly learn, but either way, they don't keep said skills when you recruit them. That could have been a way to breathe more life into the game later on and add more variety.
- Traps, traps everywhere. Of course you can't see them until you either stand on them or swing your weapon at them, which makes Monster Houses in particular a huge pain in the ass. Traps can also set each other off, ie an arrow trap shoots an arrow that lands on an explosion trap, knocking you to 1hp, then an enemy that was nearby slaps you and finishes you off. Explosions traps can also spawn next to each other, and one will set off another. Boom.
- You can be attacked through walls, or even rooms away. Huge AoE status effects, projectiles, etc.
- Some of the girls are also just a pain to recruit. There is no "general" method of recruiting, each girl has their own conditions, and some are awful. The oni, dragons and fishgirls have obnoxious minigames you have to both prep for AND then play. Other girls have bizarre conditions like "be defeated by the player, while the player is under 3 status effects at the same time, and then may join at a random chance"
- Some of the girls are also just a pain in the ass to fight. Great, several consecutive floors of these a$$hole centaurs and their arrows that hit your entire team from across the room while also getting 2 turns to your 1 and being able to knock you away. The rats suck too.

To summarize, this is a fairly reasonable and fun roguelike in the beginning. But the later into the game you get, the more garbage is introduced, and dealing with it becomes a draining burden that limits your freedom heavily and requires constant neuroticism to keep track of and prepare for, for at times only a CHANCE of mitigating it, if at all. It just becomes frustrating and exhausting.

Updated this review after getting further into the game. I'd leave a neutral review if possible, but since I can't, I'll leave a "not recommended" just so anybody looking at that section of the reviews before buying has something more to go off of, as the most detailed negative reviews of this game are all in japanese so far. TLDR: It's a roguelike with a focus on party building that is relatively fun for about 30-80 hours depending on the player, that drops off hard into tedium, lack of depth and a lot of "!@#$ the player" mechanics later. Your tolerance for bull!#@$ and your love for monster girls will play a heavy factor in whether this game is worth it, but if you're thirsty for a monster girl game that isn't just crappy eroge, this will scratch an itch. The good: - Many types of monster girls you can recruit. Most bases are covered, a few aren't. - Core gameplay is initially engaging and satisfying - The (free) music choices are excellent. - Until much later in the game, it isn't too punishing for a roguelike. Fruits of resurrection help a lot. The bad: - Whatever you think of the art direction aside, many of the areas are boring to look at and many of the girls look same-y. Some models and animations are very unpolished and janky. - Each type of monster girl has 4 tiers, each with a sizeable power gap between them and a different color palette. You can't "promote" girls, and while technically you can raise even a tier 1 to be as strong as a tier 4, it would be very time consuming versus finding a tier 4 you like the look of. - Monster girls have level caps, usually starting at 20-40. Once a girl is close to her cap, you return her to level 1, gaining a VERY small boost to her base stats and increasing her level cap by 10. This works fine for the early game, but in the post game stuff, wellllll... the max cap is 200. Raising it by a mere 10 at a time is just miserable. Especially if you recruit a new girl you want to get to a useable state, depending how far you are into the post-game dungeon, it can be hard to want to go through that grind. It becomes a sh!tty version of the similar system in Disgaea. - After the first couple of dungeons, we have mandatory* gimmick dungeons. What kind of gimmicks? Nothing interesting, just restrictions. No bringing in items, no bringing in monster girls, no recruiting monster girls. Huh? Who asked for this? The appeal of the game IS the monster girls and accumulating items. Without those it's not a particularly engaging roguelike. *Thankfully you can skip these dungeons to get back to the main game if you choose to, but I don't know why they exist in the first place, especially before post-game. - There are a LOT of useless items, and a LOT of items that are dangerous to use without knowing what they are. Items beyond the first few dungeons are all unidentified by default, and identifying them every time quickly becomes a chore due to how many are just utterly pointless. You will find yourself stuffing your inventory with dangerous-to-use items to bring in with you just to have them pre-identified so you don't ruin a run with an unid item. Alpha monsters (super powered up minibosses that can spawn on any floor) usually require some kind of prep work to safely deal with, but the items they drop are almost never worth it. I've never had them drop anything better than what I can get from using Magic Keys. - Base inventory space is incredibly limited, and managing storage pouches is clumsy and cumbersome. I've lost count of how many times I've fumbled going into a pouch to grab an item to hurl, to instead hurl the entire pouch itself, pelting the enemy in their stupid face with my pouch and destroying it in the process. - There are a lot, a LOT of hazards that can lead to instant death, party member death or item loss, both RNG and non RNG that you need to account for. You will need a lot of inventory space for this, and you will be wasting most of your gear/girl customization on this, too. Most progression in this game is entirely building around mitigating bullshit. About 95%, compared to 5% of you actually feeling like you're getting stronger. The amount of preparation you will be doing purely for the purpose of not getting scummed out by some bull!@#$ HEAVILY limits your options in almost every area of the gameplay. - There's also plenty of hazards you can't mitigate or prepare for, including ones you can. What do I mean by that? Those anti-rust and anti-steal symbols you stuck on your gear? Late game monsters will just outright ignore them, they don't work. - What skills monster girls can learn are heavily restricted. Some girls far outclass others. There is a post-game difficulty setting where enemy monster girls randomly learn different skills every few floors. I don't know if these include skills they can't regularly learn, but either way, they don't keep said skills when you recruit them. That could have been a way to breathe more life into the game later on and add more variety. - Traps, traps everywhere. Of course you can't see them until you either stand on them or swing your weapon at them, which makes Monster Houses in particular a huge pain in the ass. Traps can also set each other off, ie an arrow trap shoots an arrow that lands on an explosion trap, knocking you to 1hp, then an enemy that was nearby slaps you and finishes you off. Explosions traps can also spawn next to each other, and one will set off another. Boom. - You can be attacked through walls, or even rooms away. Huge AoE status effects, projectiles, etc. - Some of the girls are also just a pain to recruit. There is no "general" method of recruiting, each girl has their own conditions, and some are awful. The oni, dragons and fishgirls have obnoxious minigames you have to both prep for AND then play. Other girls have bizarre conditions like "be defeated by the player, while the player is under 3 status effects at the same time, and then may join at a random chance" - Some of the girls are also just a pain in the ass to fight. Great, several consecutive floors of these a$$hole centaurs and their arrows that hit your entire team from across the room while also getting 2 turns to your 1 and being able to knock you away. The rats suck too. To summarize, this is a fairly reasonable and fun roguelike in the beginning. But the later into the game you get, the more garbage is introduced, and dealing with it becomes a draining burden that limits your freedom heavily and requires constant neuroticism to keep track of and prepare for, for at times only a CHANCE of mitigating it, if at all. It just becomes frustrating and exhausting.