Bakumatsu Revolution will be free to download via PlayStation Network and will feature a full ten-hour quest, which can be played solo or cooperatively with up to three others (Monster Hunter style). According to IGN, players will even be able to freely distribute the game through PSP-to-PSP wireless connectivity.
Of course, there's always a catch. While the core game will be free, for-pay add-ons, such as downloadable items and quests, will be available after release. Essentially, this is the "freemium" model that's been successfully utilized by many PC MMOs and casual titles, especially in Asian markets.
Bakumatsu Revolution will be available on June 25 in Japan; but no plans for a North American release are currently in the works.