This seems to be the cheapest price at the moment, Amazon are £27.46, Game are £29.99. The seller funboxmedialtd has currently sold 645 copies of the game with 99.8 positive feedback.
About Lego Worlds:
Build and play without limits with LEGO® Worlds! LEGO® Worlds is a digital LEGO® play experience where any creation is possible. Fans of all ages can create and customise their own LEGO® world, explore and discover unexpected treasures and share creations with friends.