Sure, here's a simple game implemented as a single HTML file using JavaScript, enclosed in script tags:
Multiplayer Game
The game consists of six players, five blue and one red. The players are represented as colored circles. Every second, the active player switches from blue to red, highlighting the current player. The game is designed to be played on a smartphone, and pictograms could be added to the player elements for visual representation if desired. Note that this is a basic example, and there is no actual gameplay or user interaction.