Sure! Here's a simple implementation of the game you described using HTML and JavaScript:
This code creates a simple game where a random emoji, represented by a span with id "emoji", moves inside a box. The position of the emoji is updated every 10 milliseconds, and if it hits the walls or corners of the box, a new random position is generated and the speed of the emoji is increased by 5%. The game is enclosed in the `
` tags and can be saved as a single HTML file.