Koei's sea-based MMORPG.

Koei tried selling its sea-based MMORPG Uncharted Waters Online to PS3 owners as a retail release. Now it's using a different tactic to get console owners logged into the game's servers and paying monthly service fees.

The company announced today the March 9 availability of a free demo version of the game. PS3 owners will be able to download this from PlayStation Store and get started with the game.

If they like what they see, they'll be able to continue playing using the same client that they downloaded. This essentially means that the PS3 will have a fully downloadable MMORPG.

Koei will share further details on the PS3 demo shortly.

The demo coincides with the March 9 release of the game's 5th anniversary update (although the 5th anniversary is actually on March 16). This update, for both PC and PS3 owners, will give the game new events, a new opening movie, a new dungeon, and other additional content.

Scenes from the new opening.

Added content for the update.