Monument Valley's new expansion, Forgotten Shores, will arrive on Android tomorrow, Nov. 20, developer Ustwo announced today.

Forgotten Shores will be available exclusively in the Amazon Appstore for the first four days of release. The wider Google Play launch will occur next Monday, Nov. 24.

"Amazon have been really committed to supporting us since the release of [Monument Valley] and sales have been surprisingly high," said Ustwo executive producer Dan Gray in an email to Polygon, when asked about the reasoning behind Forgotten Shores' timed-exclusive release on Amazon.

"They've supported us in a number of ways during a crucial release period to make sure our Android version could be available as soon as possible and we're really happy we get to give Android users a version so soon after the iOS release," added Gray. Forgotten Shores debuted on iOS last week as a $1.99 in-app purchase in Monument Valley, and the expansion will cost the same on Android.

Monument Valley itself, which is regularly priced at $3.99, is available at no cost today from Amazon as the Appstore's free app of the day. The offer expires in nine and a half hours, at 2 a.m. ET tomorrow. Gray clarified to Polygon that the Appstore version of Forgotten Shores won't be compatible with the Google Play version of Monument Valley. So Android players who want to get the expansion before its launch on Google Play next week, said Gray, should download the original game from the Appstore for free today.

You can check out a trailer for Forgotten Shores below. For more on Monument Valley, check out our full review.