If you live in Europe (United Kingdom, Ireland, Germany, France, Spain, Italy, Belgium, the Netherlands, Portugal) or Russia, you can register your 3DS XL on Club Nintendo to get Professor Layton and the Miracle Mask for free!
If you already have Miracle Mask, you can also get one of these games:
- New Art Academy
- Super Mario 3D Land
- Nintendo Presents: New Style Boutique
- Freakyforms Deluxe: Your Creations, Alive!
If you already registered your console, you can log in to Club Nintendo and get the download code. If not, make sure to register it before January 15, 2013!
You will be able to download the 1 free game in January 2013.
Source / Info: http://microsite.nintendo-europe.com/3DSXLGamesPromotion/termsENG.html