Here's a possible implementation of the game:
In this game, the player is a stick figure skiing down a hill and he has to avoid randomly generated obstacles to win. The player can move left and right using the arrow keys. If the player hits an obstacle, the game is over and the page is reloaded to start a new game.
The `player` object contains the player's position, size, speed, image (an emoji), and angle (used to rotate the image). The `obstacles` array contains objects representing the obstacles' positions and sizes.
The game loop updates the player's position based on input and the obstacles' positions based on the player's speed. It then checks for collision between the player and the obstacles, and displays a game over message and refreshes the page if there is a collision.
The `generateObstacles()` function generates five obstacles with random positions and sizes at the beginning of the game.
The canvas is set up to fill the entire screen and the game objects are drawn using the canvas context's methods.
Overall, this implementation should meet the criteria of the prompt by providing a playable game in one HTML file with inline JavaScript and emoji graphics.