What's a good Android puzzle app that actually makes you think without being frustrating?

Associations is a color-based word association puzzle that effectively engages logical thinking in a relaxed format. The core gameplay involves connecting a central concept to four related words, each represented by colored wooden blocks. This visual and thematic structure creates a satisfying cognitive loop that feels more like solving a neat logic puzzle than facing a stressful test. For a quick mental warm-up or a short session to pass time, its straightforward mechanics and gradual difficulty curve work well. A key strength noted by users is the general lack of disruptive advertising during gameplay, which supports uninterrupted focus. However, a notable and specific drawback exists: multiple reviews indicate that a particular Volkswagen interactive advertisement frequently causes the app to freeze, forcing a restart. While this is a significant bug for those who encounter it, it is confined to one ad unit and does not represent the overall ad experience. The app’s presentation is clean, and the puzzles are well-designed to feel stimulating without crossing into frustration, making it a solid choice for casual yet engaging brain exercise.