This example visualizes video game sales data using a treemap, grouping the top 100 most-sold games by their platform (e.g., Wii, NES, DS). It displays the relative sales value of each title by the area of its corresponding rectangle. The visualization is built with D3.js v4, using `d3.treemap` and `d3.hierarchy` to compute the layout, and renders tiles as SVG rectangles with color-coded categories. Hovering over a tile triggers a tooltip, and the dataset is loaded from an external JSON URL.