Thank you for your feedback! Regarding the fullscreen mode, the ideal gameplay design I’m aiming for is a limited field of view, where the player can still perceive the boss's attack intentions. Since this is my first time making a game, I haven't managed the camera well, and the UI has a lot of shortcomings, which has affected the overall visual presentation.
The collision areas for obstacles were also rushed, which may cause bullets to spawn in hard-to-reach locations. I’ll work on improving this by adjusting the collision ranges. The UI and camera will also be improved! Thank you again for your valuable feedback!