The official Pokémon website has announced the new game that allows players to unlock an Eeveelution in the Pokémon Dream World later this year. Unlike the Japanese Eeveelution game
Pokémon Labyrinth Great Summer Research Group (ポケモンラビリンス 真夏の大調査団) that was a large an involved flash game, Play to Befriend a Pokémon! is based off the classic Taito game
Arkanoid. Players are required to have a Pokémon Trainer Club to play the game so that the resulting Eeveelution can be linked and stored with an account.
As you clear blocks, orbs representing each of the 7 Eevee evolutions fall. Collecting these is the key to winning the one you want! After the 4th level, the orbs that you collected are counted up and the majority of the orbs that you collect determines the Eeveelution you will receive from the Pokémon Dream World download. When you finish the game, you'll have the option to keep the Pokémon you've earned but once you've chosen to keep the Eeveelution, your decision is final and you cannot change the Pokémon. You can play the game over again even after you've finalized your Pokémon selection.
Press Release
Head to the Pokémon Fun Zone to befriend a Pokémon that you can meet via the Pokémon Global Link!
Play this game on Pokemon.com, and you'll be able to meet one of Eevee's seven evolutions in the Pokémon Dream World when the Pokémon Global Link website launches this spring! The Pokémon Global Link is an awesome new website connected to the Pokémon Black Version and Pokémon White Version games for the Nintendo DS™. To get ready for the launch of the Pokémon Global Link, head to the Pokémon Fun Zone to play a fun new minigame, where you can befriend one of Eevee's evolutions! The Pokémon you befriend will appear when you visit the Pokémon Dream World, one of the amazing new features of the Pokémon Global Link. From there, you can receive that Pokémon in your copy of the Pokémon Black Version or Pokémon White Version game!
Before playing this game, be sure to sign into your Pokémon Trainer Club account. After you complete the game, the Pokémon you befriend will be transferred to your account. When the Pokémon Global Link website launches this spring, the Pokémon you befriend will be waiting for you when you visit the Pokémon Dream World!
Sign in to your Pokémon Trainer Club account and befriend one of Eevee's evolutions now!
Source:
http://www.pokemon.com/us/news/fz_eevee_pgl_announce-2011-03-28/