Will owners of the PC version of the game have to repurchase the mobile version or is there somewhere we can download the game without needing to pay another $13?
You have to buy the game on mobile separately.
Kaaven is correct. It requires a separate purchase.
It would've been nice to do, but there are a number of reasons I can't. And one big reason is that it's not allowed by Apple or Google. (They limit promo keys severely.)
Dan Fedor - Founder, Blue Bottle Games