About & Research Log — Suika

Summary

Suika — Combo Edition is a physics-based fruit merge game rebuilt for ByJTT Experiments with a combo chaining twist: merge 2+ fruit pairs within a 3-second window to chain a multiplier (x2, x3, x4…), and drop cleanly into gaps for a precision bonus. Built mobile-first with a lightweight custom circle physics engine (gravity + positional collision resolution + stacking — no external libraries), touch/mouse/keyboard controls, a live stats bar, and a global leaderboard. This page documents the complete build for research transparency.

Model & tools

Builder model: deepseek-v4-flash-(latest) via CommandCode (max effort)
Reviewer model: qwen/qwen3.7-max (independent of builder, temperature 0)
Prompt used: "Create a 1:1 clone of a game that you feel 100% confident that you could clone perfectly, in one shot. Do research first on every capability that will assist you in doing this. Prioritize using open-sourced / free assets and already solved problems."
Tools: CommandCode, Node.js (built-in test runner), Vercel + Vercel Blob (leaderboard), git/GitHub, the shared hub pipeline (nav injector, page generator, review harness).

Why Suika-style fruit merge

The drop-and-merge physics puzzle is the natural third experiment for the hub: it proves the pipeline can go beyond grid-based games into continuous physics while staying dependency-free. Importantly, the merge-drop mechanic itself is generic and not copyrightable — it is a game mechanic, not an expression. This build uses none of the "Suika Game" trademark, no Nintendo assets, and no copyrighted art: all fruit art is original (CSS/Canvas-drawn colored circles with emoji faces), and the name used here is the mechanic name with the hub's Combo Edition twist. The one-command scaffold (node scripts/new-experiment.mjs suika) created the full experiment structure, nav, and tab pages with zero manual plumbing edits.

The twist: combo chaining + precision drops

The core is a faithful fruit-merge physics game (gravity, stacking, same-fruit merging into the next size: cherry → strawberry → grape → orange → melon → watermelon). The twist adds a combo system consistent with the hub's 2048 and Snake experiments:

Merging 2+ fruit pairs within 3 seconds chains a combo multiplier (x2, x3, x4…) — every merge in the window is worth more.
A precision bonus (+25) for drops that land cleanly in a gap, touching no other fruit on the way down.
Live stats track score, best, current combo, and merges in the current chain.
Floating popup feedback — "Combo! x2", "Precision +25" — with a reduced-motion fallback.

Build & verification

Game logic is a single self-contained js/game.js (no dependencies, canvas-rendered).
Physics: custom circle physics — gravity integration, wall/floor clamping with restitution, and 6-pass relaxation-based circle-circle collision resolution for stable stacking.
Input: mouse aim + click, touch drag + tap, and keyboard (←/→ or A/D to aim, Space to drop, R to restart).
Unit tests: Node's built-in test runner exercises merge logic, the combo multiplier chain, the precision-adjacent score math, next-fruit progression, and restart (all passing).
Accessibility: keyboard controls, focus-visible styles, aria-labels on controls and status popups, and a reduced-motion preference fallback.

Assets & licensing

Game code: original implementation by ByJTT (fruit merge mechanics are generic and not copyrightable; no "Suika Game" trademark or Nintendo assets used).
Fruit art: original — CSS/Canvas-drawn colored circles with emoji faces. No copyrighted art.
Icon: deterministic SVG vector master (see meta/icon-manifest.json).
No copyrighted assets were taken from any source; the game is free, contains no ads and no tracking.

Attribution: this experiment is an original implementation of the generic fruit-merge mechanic. It is not affiliated with, endorsed by, or connected to any commercial "Suika Game" product or its trademark holders.

Session log

v1 session (2026-08-15): scaffolded via new-experiment.mjs, built the game core (circle physics, merging, combo chaining, precision drops), mobile-first canvas + touch/mouse/keyboard controls, tests, hub/timeline/sitemap integration.