English Title: planetarian ~chiisana hoshi no yume~
Japanese Title: planetarian 〜ちいさなほしのゆめ〜
Publisher: Prototype
Developer: Key / VisualArt's
Genre: Visual Novel
Released: Aug. 24, 2006
Product Codes: SLPM-66472 / JAN 4933032003953

A so-called "kinetic novel", which differs from your standard visual novel in that there are no choices or branching paths -- you simply read the story to proceed through the game. The story centers around a man who finds a malfunctioning robot in an abandoned city.

This is a port from the PC version released a few years prior, which actually saw a fan-translated English release. By most accounts, it's quite good, and only takes about 4-5 hours to get through depending on how fast you read. I should really get around to reading through it someday...