Here's an example of a simple game based on your requirements. It is a game where the player collects sun to build plants and fight against the zombies. It can be played on a smartphone, and I'll be using pictograms to represent the game elements. Below is the code for the HTML file:
Please note that this example provides the basic structure of the game and only includes the drawing functions for the game elements. You would need to add additional logic for collecting sun, building plants, and fighting against the zombies as per your game requirements.