Before starting to go into deeper details about the development of the game I wanted to talk a bit about the licensing and pricing of WD.
WD is an open source effort and its code will be released under the GPL 3 license. This means that you will be free to download its code, take a look at it, change it and even release your custom version so long as you also keep it free (free as in freedom, to quote Richard Stallman).
So does it means that you will be able to get it for free (as in free beer)? Well, yes! When it will be finished you will be able to download it from free.
On the other hand we also plan to offer a paid version (at a small price, less than five dollars) to obtain some extra features that we will define during development, for example I am partial to the idea to offer a couple more levels inside the paid version, that means mostly new art assets and new scripts.
Of course no DRM will be used and the new assets and code will still be free, so there will be nothing stopping you to just repackage the paid version and just share it for free, however I think that the people who enjoyed the game to the point of wanting a couple of new levels (and this in itself will already be a huge success!) will be happy to contribute with a small amount to our efforts. You can think of it more as a donation to support the game.
Regarding the artistic contents we have still to decide, but keeping in line with what I have said above we will probably release everything under a CC BY-NC-ND license.
What do you think about this kind of distinction between paid and free version?