Planetarian: Chiisana Hoshi no Yume
is a Japanese post-apocalyptic visual novel. It was developed by Key, a brand of Visual Art's whose previous works include Kanon and Air. It was released over the Internet on November 29, 2004 playable on Windows PCs. It is rated for all ages. The game was later ported to the PlayStation 2 (PS2) and PlayStation Portable, as well as mobile devices.