Hit up HumbleBundle.com to buy it, where you'll get DRM-free downloads of Avadon, Canabalt, Cogs and Zen Bound 2 no matter how little you pay. If you pay more than $1--and you surely will--you'll get Steam keys for all games except Canabalt, which isn't sold there. Then, should you spend more than the current average price, you'll get Swords & Soldiers thrown in too.
All five games are making their Android debut in the Bundle, and it's first time several are on Linux. Avadon is only for Android tablets, though, as it's a bit too much for a small phone screen.
This latest Humble Bundle will be sold until 4 p.m. PDT on April 2. Given the bundleer's track record, we can probably expect a surprise addition or two to the package along the way.