Here's a polished version of your job posting for a mobile game developer:
Overview:

We are seeking an experienced mobile game developer to create an engaging game compatible with both iOS and Android devices. The ideal candidate will possess a strong understanding of game mechanics, user experience, and mobile app development.
Responsibilities:

    Design and Development: Create and implement game mechanics, user interfaces, and engaging gameplay features.
    Testing: Conduct thorough testing to ensure the game runs smoothly on various mobile platforms.
    Optimization: Optimize the game for performance and user experience across different devices and screen sizes.
    Collaboration: Work closely with our design and marketing teams to align on vision and user engagement strategies.

Qualifications:

    Proven experience in mobile game development for iOS and Android.
    Strong knowledge of game design principles and mechanics.
    Familiarity with game development tools and programming languages (e.g., Unity, C#, or similar).
    Excellent problem-solving skills and attention to detail.
    A passion for gaming and a portfolio showcasing previous work in game development.

Why Join Us?

    Opportunity to work on exciting and innovative game projects.
    Collaborative and creative work environment.
    Room for growth and advancement within the company.

If you're passionate about gaming and have a proven track record in mobile game development, we’d love to hear from you! Please submit your resume and portfolio to apply for this exciting opportunity.

Feel free to adjust any parts of the text to better suit your needs!