Sudoku Vault is a logic-based puzzle game featuring 4x4, 6x6, and 9x9 boards — each with four difficulty levels: Basic, Normal, Hard, and Expert. Whether you're a beginner or an expert, every grid offers a fresh challenge for your mind. Use smart NOTES to keep track of possibilities, and when you want to check your progress, tap the CHECK button — it will remove incorrect inputs and lock the correct ones, helping you stay focused on the solution.