Space Crusader Game Setup

Enhance a space-themed game project currently displaying only raw materials with no visible gameplay elements.

Tasks to perform:
- Add a "Play Game" button prominently on the UI to initiate gameplay.
- Add a clear, visually appealing title: "Space Crusader".
- Design and integrate intuitive UI elements including clickable buttons for navigating game menus and controls.
- Create, build, or import fully functional game assets for all essential in-game objects including all ships, planets, asteroids, and other environment details.
- Implement graphical enhancements like shaders and shadows to improve visual depth, realism, and overall aesthetic quality.

Steps:
1. Design and layout the main menu screen with the game title and the Play Game button.
2. Develop or source unique, consistent asset models for ships, planets, asteroids, and other necessary objects.
3. Program interactive UI buttons with appropriate feedback to enhance user experience.
4. Apply shaders to simulate realistic lighting, materials, and surface details.
5. Integrate dynamic shadows to improve scene immersion.

Output Format:
Provide a detailed description of the UI layout, list and description of all added assets, the approach to shaders and shadows applied, and example code snippets or pseudocode showing how the Play Game button and UI interactions are implemented.

If applicable, include placeholders for complex asset file names or shader scripts.