Sure, I can help you create a simple Robot Tower Defense game using HTML and JavaScript. Here's an example implementation:
In this game, the objective is to prevent humans from reaching the robot cage. The game board is a 200x400 pixel area represented by the `game-board` div. The human is depicted by a pictogram and moves from top to bottom, while the robot is represented by another pictogram and can shoot bullets to eliminate the humans.
To play the game on a smartphone, you can save the above code in a single HTML file and open it in a browser on your smartphone. The game can be played by tapping the screen to shoot bullets and pressing any key to start the game. When a human reaches the robot cage, the game ends with an alert message.
Please note that you would need to provide your own pictogram images for the humans and robot, and update the URLs in the CSS accordingly.