The offer is open only to players from certain regions in Europe and comes with additional requirements, such as registering a 3DS or 2DS for the first time before a deadline. Detailed terms and conditions can be found below.
Those who qualify will be able to choose one of the following games for free:
In order to qualify, participants must register their 3DS, 3DS XL, or 2DS on Club Nintendo between September 11 and January 12.
As well as this, they will need to register one of the three games (either Smash Bros or one of the Pokemons) between October 3 and January 12.
Those who buy the game from retial, as opposed to the Nintendo eShop, will also need to fill out a survey.
Once the required tasks are completed, Nintendo will send a free game download code once a user sends a request via their Club Nintendo account. That code must be requested before February 12, and must be redeemed before March 12.
Eligible countries: United Kingdom, Ireland, Germany, Austria, France, Spain, Italy, Belgium, the Netherlands, Portugal, Switzerland, South Africa, Russia.
Rob Crossley is GameSpot's UK News Editor - you can follow him on Twitter here