Sudoku - Classic Sudoku Puzzle is a popular, ad-supported brain-training app that excels in core gameplay mechanics but suffers from significant user backlash due to aggressive monetization. While it maintains a strong rating, the declining sentiment trend suggests that the current ad-heavy strategy is alienating its core user base. The app successfully targets casual puzzle players with a clean, offline-capable interface and unique input features. However, to remain competitive, the developer must address the intrusive ad experience and resolve platform-specific technical bugs that are currently hindering user retention.