This is Sputnik. BrainGames are novelty mind puzzles available on Instagram. For their promotion we designed posters that work as puzzles. We based our concept on the classic observation game of spotting differences and created a series of seven twin puzzle posters, featuring a large spot made of intricate optical illusion patterns with varying levels of difficulty. From Simple (E) to Medium (M) and Hard (H), all patterns are based on repetition and complexity to engage and intrigue viewers. The posters were hung in one of Athens's busiest shopping centres and on derelict old-charm house facades in a hip Athens neighbourhood, frequented by locals and visitors alike.