Bastion's 69p on iOS as part of a Warner Bros. title sale on mobile platforms.
Super Giant Games originally released the title, an action-RPG, on XBLA, before refitting it for mobile last year. It's normal price is £2.99.
Other iOS titles in the same-price are promotion are Man of Steel, LEGO Harry Potter Years 5-7, Batman Arkham City Lockdown, Scribblenauts Remix, LEGO Batman DC Superheroes, and Midway Arcade.
Those titles on Google Play - Man of Steel, Batman: Arkham City Lockdown and Scribblenauts Remix - are also available for 69p.
We've reached out to Warner Bros. for clarification as to exactly when this sale ends, but haven't had a specific date acknowledged. It could be this weekend or later next week. Basically, if you want to pick the game up cheaper, do it now rather than later.