Fill the Coffee Cup
In game design, 'Fill' is a fundamental mechanic that transcends genres. It can manifest as completing a puzzle grid, replenishing a health bar, or satisfying a collection meter. This simple action creates a powerful feedback loop, offering players tangible progress and a sense of accomplishment. The act of filling—whether it's a map, an inventory, or a skill tree—often serves as the core progression driver, transforming abstract goals into satisfying, visual completions. It taps into a basic human desire for order and closure, making it a versatile and enduring design pillar.