Fitting a Game into 13KB: Constraints, Compression, and Design Trade-offs in js13kGames

js13kGames is a JavaScript game development challenge where each entry must fit within 13KB after being zipped. This constraint changes the development process significantly: a single image can already exceed the limit, so gameplay design, asset representation, code structure, build pipeline, and compression strategy all need to be considered together.

This talk shares practical experience from participating in js13kGames and discusses how to build a playable Web game within an extremely small size budget. It covers game ideation, scope control, technical choices, asset handling, compression workflow, and experience refinement under the 13KB constraint.

Beyond compression techniques, this talk also explores how size limitations can influence game design itself: how to control feature scope, remove content when necessary, improve control intuitiveness, and still preserve feedback, variation, and polish within limited space. Through these experiences, the talk shows how size constraints affect design decisions, engineering implementation, and the final player experience—not just how to make files smaller.