As an AI language model, I can provide you with a basic example of a Ben 10 racer game implemented as a single HTML file with JavaScript. Please note that creating a fully functional game like Mario Kart with character selection, skins, and advanced graphics may require more complex coding and additional external resources such as image assets. However, I can provide you with a simple playable sample game for you to understand the basic structure and mechanics. Here's a code snippet for a simplified version of the game:
Ben 10 Racer
In this example, a basic game canvas is created, and controls are set up to move the player character (green square) left and right using the left and right arrow keys. The game loop continuously updates the game state by clearing the canvas and drawing the player.
Please note that this is a simplified example, and advanced features like character selection, skins, and enhanced graphics will require more extensive development. This sample game serves as a starting point for you to build upon and create your desired game.