You are watching a piece of internet history from the early 2000s. Before YouTube and HTML5 took over, Macromedia Flash was the king of the web. It allowed creators to build vector-based animations that were small enough to load on dial-up internet but rich enough to create entire worlds.
War of the Icons represents the peak of "stick figure culture" - a time when the internet was wilder, screens were smaller, and viral content spread via email forwards rather than algorithms.