"Cursed Island ~Once You're Bitten, It's All Over~ (Smartphone Ver.)" is an adult adventure game for smartphones developed by the circle "Hige to deko." Built around themes of female protagonist, restraint, confinement, and trance/suggestion, the title has recorded 143 sales to date.

The game is set on an isolated island. The moment the protagonist and her companions arrive at the island chosen as a training camp destination for their Occult Research Club, they are ambushed by a horde of monsters bearing massive fangs. As the group is scattered, a survival scenario unfolds in which the player must fight to stay alive and escape the island. The story goes far beyond a simple escape narrative, incorporating a wide variety of situations including brainwashing, breaking-in, imprisonment, lewd massage, choking, and biting. The circle has explicitly noted that the game contains ryona content, including depictions of bloodshed and choking.

In terms of game systems, the title features simple action-style combat. Rather than being a pure visual novel, the inclusion of combat segments gives the game a more interactive, gameplay-driven identity.

Regarding the scale of adult content, the game officially lists 48 base CGs (not counting standing sprites) and over 150 scenes. The sheer number of scenes suggests that multiple branching scenarios are prepared for each character.

The game features four heroines. The protagonist, Mizuha Tsukishima, is a kendo club member with a cool yet strong-willed personality, depicted as someone who confronts unreasonable situations out of a sense of justice. Mayu Shinonome is Mizuha's best friend and a member of the Occult Club—cheerful and earnest by nature, yet harboring insecurities about her body. Rui Hisaki is a mysterious woman who happened to be on the same boat, characterized by her isolated demeanor and refusal to engage with others, with hints that she came to the island with a specific purpose. Sara Hyoudou is a half-Japanese archaeologist who gets caught up in the chaos while investigating ruins on the island. She is designed as a character full of contrasts—unconsciously confident in her appearance while also holding a black belt in karate.

Given the breadth of scenarios and the number of characters, the overall play volume is expected to be substantial. The circle has openly announced that the game contains extreme content, positioning it as a title that requires tolerance for certain types of depictions. The structure—combining erotic elements and a combat system with a survival backbone—reflects a design philosophy aimed at delivering a multifaceted experience rather than confining itself to a single genre.