Introduction: Happy Color - Paint by Number is a delightful and engaging mobile game developed by X-Flow. It's a coloring book app with a unique twist: instead of coloring on paper, you paint by numbers on your smartphone or tablet. With its vast collection of beautiful and intricate coloring pages, it has become a favorite pastime for many users, providing relaxation, creativity, and a touch of nostalgia.Gameplay (4/5): Happy Color offers a simple yet satisfying gameplay experience. Players choose from a wide variety of coloring pages, each divided into numerous small sections marked with numbers. The objective is to fill in these sections with colors according to the corresponding numbers. As you progress, the pixelated image gradually transforms into a stunning piece of art.The game's interface is user-friendly, making it accessible for all age groups. Tapping on a numbered section automatically selects the appropriate color from the palette, eliminating the need for manual color selection. This streamlined approach ensures that the game is enjoyable even for those who aren't typically into digital coloring.One downside is the limited interaction within the app. While the primary focus is coloring, some users might appreciate additional features like the ability to save and share their completed artworks or engage in a community aspect, such as comparing their creations with others.Graphics (4.5/5): Happy Color's graphics are a highlight of the game. The coloring pages are meticulously designed, offering a wide range of themes, from nature and animals to mandalas and abstract patterns. The app's pixel art style adds a nostalgic touch, reminiscent of traditional paint-by-number kits.The colors are vivid, and the transitions from one section to another are seamless. Zooming in and out for detailed coloring is smooth and intuitive. While the game doesn't aim for realism, it excels in delivering aesthetically pleasing visuals that enhance the coloring experience.Sound (3/5): Happy Color's sound design is simple and unobtrusive. It includes calming background music that provides a soothing ambiance as you paint. However, the music can become repetitive over time, and some users might prefer the option to use their device's music library or play in silence. Adding sound effects related to coloring actions could also enhance the audio experience.Monetization (4/5): The game follows a freemium model, allowing users to play for free while offering in-app purchases for premium features. The primary monetization comes from ads, which appear between coloring pages. These ads can be removed with a one-time purchase, making it an attractive option for those who want an ad-free experience.Additionally, Happy Color offers a subscription plan called "Happy Color Plus," which provides access to premium coloring pages and removes ads. While the subscription offers value for dedicated users, the core experience remains enjoyable without it.Conclusion: Happy Color - Paint by Number is a delightful and relaxing coloring book app that brings the joy of coloring to your mobile device. With its beautiful pixel art, user-friendly interface, and a vast collection of coloring pages, it's a great way to unwind and express your creativity.While the app's simplicity is part of its charm, it could benefit from additional features for sharing and interacting with the community. Nevertheless, Happy Color is an excellent choice for anyone seeking a peaceful and creative escape in the form of digital coloring.Overall Score: 4/5