Sure! Here's an example of a game where a flying cube shoots lines at randomly generated objects that shoot back at the player. The game will be playable on a smartphone and will use pictograms where possible. Remember to save this code in a single HTML file.
This code will create a canvas element where the game will be played. The player is represented by a blue cube that can shoot projectiles (yellow circles). The enemies are represented by red circles. The player needs to shoot the enemies while avoiding collision with them. The game keeps track of the score, and when the player collides with an enemy, the game ends and a message displaying the final score is shown.