Sure! Here's an example of a simple Mario-themed platformer game with 10 levels and a boss at level 10. The game is implemented as a single HTML file and uses JavaScript for the game logic. It is designed for smartphone operation and utilizes pictograms for visuals.
Note: This is a basic implementation and can be expanded upon with additional features and improvements.
To play the game, you can copy the above code into a blank HTML file and open it in a smartphone browser. The game consists of a character represented by a blue square (player) that needs to jump on platform represented by smaller red rectangles to reach the boss represented by a pink square (boss) at level 10. The player can move left and right on the platforms using touch controls, and they must avoid falling off the screen or colliding with the boss until they reach level 10.