Monsters Abyss: Operation
by Wataru Nagai Magic Cave Tei
2DCG
Adventure
Animated
Big Ass
Big Tits
Censored
Creampie
Fantasy
Female Protagonist
Groping
Japanese Game
Monster Girl
Rape
RPG
Tentacles
Turn Based Combat
Vaginal Sex
About Monsters Abyss: Operation
Monsters Abyss: Operation is a Unity adult game from Wataru Nagai Magic Cave Tei. The latest build is 3.41, updated on November 22, 2025. It runs on Windows. Text is in English (MTL), and the game is censored. The game uses hand-drawn 2D art with animated scenes, and you play as a female protagonist. Players tag it with adventure, fantasy, monster girl and RPG, alongside big ass, big tits and creampie content.
Game description
This is a short demo, that will introduce you to the game mechanics.
Monsters Abyss: Operation screenshots
Download Monsters Abyss: Operation 3.41
Changelog
Changelogs
v2.1
Here. 2 new enemies, Bearhugman and the female version, 3rd and 1st options in the lime top area.
v1.2
・ Reduced freeze bugs
・ Changed damage
・ Implemented voice in dungeon (some still)
[Monsters that can be played now]
◆ Slime (battle)
magical fountain → "rubble"
magical supply → "magical capsule" option "crush all"
◆ King Slime (Battle)
Blue Wall → "Slime Group" option "Follow"
* The freeze bug has been resolved.
◆ G Escargot's Tentacle (Battle)
Magical Fountain → "Slimy Big Stone"
Dim Cave → "Passage with
Conflict Traces" Option "Run Through " * Bug that freezes when damaged to HP 25 or less alive and well
currently investigating the cause
◆ Baby Purple (Event)
Flag After seeing "Dim Cave-> Hole that smells of
demons", Dim Cave-> "Wriggle Darkness"
◆ Heavy Blush (Event) With
50 or more HP, the cliff blue wall → "Magic circle that feels a sign"
* The freeze bug has been resolved.
Since it has been organized so that it works normally to some extent, the operation test will be done in 1.2 this time. The next update will be "Monsters Abyss Trial Version 1.0", and the remaining bugs will be wiped out and new monsters will be added in the February 2022 article, Gatchiri Plan and above. After that, it will be updated to April, June, and August with the goal of once every two months. In the month when the trial version is not updated, some animation will be uploaded.
We have updated the above contents of the Gatchiri Plan accordingly, so please check again.
Player reviews
Player rating
3.5 / 5 · 6 ratings
Written reviews
6 · avg 3.5★
Positive (4–5★)
50%
Latest review
2025-08-22
What players say
Reviews are mixed, praising visuals and voices while criticizing bugs, translation, and shallow gameplay.
5★
2
4★
1
3★
1
2★
2
1★
0
Players like
- Smooth live 2D animations
- Acceptable heroine voice acting
- Monster and tentacle content
Common complaints
- Bugs and missing content
- Basic clicking gameplay
- Broken English translation
Best for players who like casual monster and tentacle adult content with smooth visuals.
Summarised from 6 written player reviews.
This review is of version 3.3 Only stage 3 is available. Though it is possible to go in and edit the game files to enable stage 1 and 2. Calling this a game stretches the definition of "game". This is…
version 3.0 first of all it says that it has MtL english translation... its a lie. it's nearly fully japanese. options/extras buttons don't even work. animations not bad but the sex scenes and the way they are used is quite…
The gameplay is pretty barebones, it amounts to a graphical choose your own adventure with some monster encounters sprinkled within, the combat with which can be summed up as "Click the mouse, if the slider is on blue, you attack/avoid…
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