Shapist, a unique sliding block puzzle game we recently reviewed for iPad, is on sale this weekend. It's also headed to iPhone and Android in the next few months. The new version will be free to try with a single in-app purchase to unlock the full game and have some different puzzles than the iPad version.

There are over 50 levels in the iPad version, and developer Ori Takemura anticipates that at least 30 of the levels on the iPhone/Android version will be different, with an adjusted difficulty curve. They have yet to settle on how they will modify the iPad version to reflect these changes. Two options they are considering is giving the new levels to their early adopters at no cost and remaking a universal iOS app that includes the updates.

The new levels will be designed to further explore what can be done with the existing special block types rather than introducing a new type. A new block type is in the works, however. That new type involves time, though Takemura didn't give me any details. If the time block works out, it would be added sometime after the iPhone and Android versions of the game are released.

Shapist is on sale on the app store for $0.99, down from its regular $2.99 for the weekend. It was on display at BitSummit, and though it didn't win any awards, Takemura says it was well-received by visitors. "One awesome guy said he didn't have an iPad and wanted to beat all 51 levels in the game during the show," says Takemura, "so he kept coming and finished the whole game on the last day."

[Buy Shapist for iPad | Try Shapist in your browser]