Sure! Here's an example of a Brawl Stars Box Simulator game written in a single HTML file using JavaScript and enclosed in script tags. This is a simplified version of the game where you can open boxes and collect items.
Open Box
To use this game, save the code into a single HTML file, open it in a web browser (preferably on a smartphone), and click on the "Open Box" button to collect items from the simulated Brawl Stars box. The collected items will be displayed below the button. Feel free to customize the appearance and add more features as per your requirements.