Thanks everyone for taking part- it's been a really fun couple of days. We just got a correct answer in, so we're really happy to crown Dave as the winner - we'll get the swag bag out to him next week, and the Limited Run edition as soon as we have our mitts on it.
In the meantime, here's the solution.
On Rosa's amazingly cool map of the island, there's a bunch of letters and numbers - a series of codes (and no, we're not going to tell you what the others are and mean!). But one of these sets is 57 52 11 and 08 29 26 - which is the co-ordinates for Boreray, the island that Dear Esther is based on.
If you join those sets of numbers on the map, they create a line - a journey. If this is superimposed in the right way on a map of the UK, the journey runs from Exeter to Boreray, via Wolverhampton and Edinburgh - the other named locations in the game. 57 corresponds to the start of the journey - so 57 = Exeter.
This was really fun, we had some great responses and we're definitely going to do something like this again sometime. If you took part but didn't win, thanks anyway - and we'll do more giveaways and comps over the next few months, so keep following us on Twitter or checking back here.