Ver.1.1.1 Update

1. Redesigned UI interface including difficulty selection and mode selection interface 2. All regular enemy planes have been replaced with recognizable styles and have simple frame animations 3. Optimize the rendering of 3D backgrounds to reduce performance pressure in some hardware environments 4. Optimize barrage collision logic, reduce ineffective collisions and repetitive damage 5. Adjusted the distribution of health and dropped items for all enemy planes, including Boss