Delta Builder

Build an evolving terrain toy titled “Delta Builder.” The cover shows a branching river depositing golden sediment into blue water, with the title and Enter. The guide demonstrates carving a channel, raising a bank, and planting a reed patch; include Skip Guide.

Use a portrait sand-table view with a river inlet at the top and open sea below. Users swipe to carve channels, reverse-swipe to raise low levees, place up to five reed patches, and rotate one inlet deflector. Hold Release Water to run a flood pulse; its duration controls volume. Water and sediment must move visibly, cut new paths, deposit bars, breach weak banks, and build land over repeated floods. Three compact goals appear only as silhouettes: grow two islands, keep one village marker dry, or create three active river mouths. Users can pause flow, dredge one short section, and continue without resetting. Weather is not random: each board shows the next two flood sizes as icons so decisions feel learnable.

After five floods, turn the final landform into a layered “DELTA PRINT” with channel branches, new land percentage, flood marks, and habitat seals. Include Undo Stroke, Pause Flood, Dredge, Run Next Flood, Save Print, and Share to Eazo. Use tactile sand, ultramarine water, ochre sediment, green reeds, and miniature contour shadows. Keep text under 14 words after onboarding. English-only interface and results, portrait-first touch, responsive, reduced-motion time-step mode, and accessible tools. Use local grid simulation with capped particles. No login, backend, external API, AI generation, background music, or autoplay audio.