999: Nine Hours, Nine Persons, Nine Doors is a gripping single-player Adventure game for Nintendo DS in which players are forced to use their problem-solving and exploration skills in a desperate life and death race against time. Set in an isolated, enclosed environment from which their is no easy escape, the lives of all nine characters of the game are defendant on the decisions made by the player. Additional features include: a mix of video cutscenes and graphic novel style presentation, puzzle-solving dependent on several factors, character dialog and exploration gameplay, diverse characters, and six possible endings that ensure a high replay value.