The product linked is the pre-order Android version which releases end of this month. By pre-ordering, you will receive two extra copies of the game; a Steam key and a DRM-free key/download. So you're getting 3 copies of the game for $9.99USD. With close to 10,000 positive reviews and a measly 414 negative reviews on Steam, this is a great bargain.
Thanks to Solostran over on Reddit for alerting me to this deal
Good deal, thanks OP!