Omega Labyrinth Z

, stylized as ''ω Labyrinth'', is a 2015 roguelike dungeon crawler role-playing video game developed by Matrix Software and published by D3 Publisher for the PlayStation Vita. The game follows a group of girls as they explore a dungeon in search of the fabled "Holy Grail of Beauty", which is said to be able to grant any wish. Protagonist Aina Akemiya searches for the Grail in order to increase her chest size, as she feels uncomfortable about her small breasts. ''Omega Labyrinth'' has been noted for its heavy fanservice content and was released on November 19, 2015, in Japan.

Gameplay

''Omega Labyrinth'' is a roguelike dungeon crawler role-playing game. The dungeon is randomly generated; each time Aina and her accomplices enters the dungeon, its map, monsters, and available items change. As players move within the dungeon, the monsters also move in a turn-based fashion. Players accumulate experience by defeating monsters and characters become stronger as they level up. If they leave the dungeon, the characters are reduced back to level 1, and all items are lost when the health bar reaches zero. Thus, missions must be completed all in one go. The goal of the game is to search for and obtain the "Holy Grail of Beauty", whilst defeating monsters and avoiding traps through utilizing items, armor, and weapons.

When entering a dungeon, players can either choose another computer-controlled character to act as their partner and enter with them, or go in alone. Although partnering up has tactical advantages in battle, it is also more risky, as the partner's items are also lost when the team gets defeated. Through defeating monsters in the dungeon, players accumulate Omega Power in addition to experience points; this increases Aina's chest size. This is accompanied by an increase in stats and if Aina reaches maximum Omega Power she enters "Hatsumune Mode", greatly powering up her status. When leaving the dungeon, Aina's chest returns to its normal size, though accumulated Omega Power can be used to purchase items.

Items obtained in dungeons are initially unidentified, with their name and effects not known. They need to be revealed using Omega Power, with an animated sequence where the player places said item between a characters breasts and shaking achieving this. Any character can be selected for this sequence, allowing players to choose their favorite. Players who do not wish to go through the scene may choose to skip it entirely. Players can also choose to strengthen their characters through the system, which is triggered by special dungeon items; this leads to one of the girl characters going into an "excited" state. Touching her during this time allows Omega Power and status increases, and are unique to each character.

In dungeons, players can also find panties and bras, which can be equipped to increase the defense of the characters, along with weapons and shields. Combinations of these can also trigger special effects. Various categories of weapons are obtained through dungeon exploration, this includes swords, lances, axes, sickles, and katanas. Items can be synthesized in dungeons using Omega Power to strengthen them. As players progress through the dungeon, characters may sometimes be captured by monsters and tapping the screen is required to free them; this provides opportunity for fanservice, as well as screenshots of characters upon falling into a dungeon trap.

Omega Power can be spent and various items purchased at the in-game shop. The game features downloadable content which can also be picked up at the shop.

Story

Characters

* (voiced by Haruka Yamazaki), the lively and energetic protagonist of the game. She is obsessed with the size of her small breasts, and thus enters the dungeon in search of the "Holy Grail of Beauty" to grant her wish of enlarging them. Although not an honor student, she is popular enough to be oftentimes the center of attention.
* (voiced by Aya Uchida), a skillful cook and Aina's best friend, and was invited by her to challenge the dungeon together. She has a voluptous chest when compared to Aina.
* (voiced by Mao Ichimichi), a quarter-Russian girl who adores Aina. "Nimble like a ninja", Saeri is a low-key girl who was also invited by Aina to challenge the dungeon with her.
* (voiced by Emi Uema), a fairy girl who "loves breasts". Pai was saved by Aina from a monster attack and thus grew attached to her. She was the one who told the protagonists the story of the dungeon and Holy Grail. Her name is a shortened version of Japanese slang word ''oppai