Based on the users' reviews of the Optical Illusions - Brain Teaser app, here are the cons and pros: **Cons:** 1. Limited level progression: Some users felt the levels were too short and didn't provide a challenging enough experience. 2. Repetitive illusions: Reviewers noted that the illusions started to repeat after a while, losing their surprise and excitement. 3. No social features: Users mentioned that the app lacked social features, such as leaderboards or multiplayer modes, which could have enhanced the experience. **Pros:** 1. Engaging and addictive: Many users praised the app's ability to keep them engaged and coming back for more despite its relatively simple concept. 2. Great for relaxation and stress relief: Reviewers found that the app helped them unwind and relax, making it a great addition to their daily routine. 3. Challenging but not frustrating: Users appreciated that the app's puzzles were challenging, but not so difficult that they became frustrating or impossible to solve.