Echoshift, the recent PSN downloadable puzzle game for PSP, is getting seven new levels, but they're only available free-of-charge for a short time.

Sony announced today that Echoshift's seven new levels are available right away on the PlayStation Store, but the offer will only last until April 1st.

Gamers new to the title will be able to download the full game and all the new add-on levels for the original $14.99 price tag. Players who have already purchased the game need only log on to the PlayStation Store and navigate to the Echoshift page, where the "echoshift Add-on Levels" should be easy to find.

Echoshift is the spiritual successor to Echochrome, a well-received PS3/PSP downloadable title that released in 2008.

The announcement comes via a post at the PlayStation Blog.

What's your take on free content post-release? Is it ever enough to get you to try a game you might otherwise have overlooked?