/build-application — a game is an application.
Map game concepts to feature layers: data/ = state + rules (+ per-tick step math), components/archetypes = entity kinds, indexes = spatial/lookup queries, transactions = moves/spawns, computed = score/status/winner, ui = view + input.
- Turn-based uses the reactive transaction → computed → ui loop, no systems (see data-lit-tictactoe).
- Real-time adds the
build-systemsphase: a per-frame tick loop (movement, collision, lifetime) driven by the scheduler, over many entities in distinct archetypes. This is where components, archetypes, indexes, and systems all carry real weight — seefeatures/ecs/systems.md.