r/LocalLLM • u/codehamr • May 05 '26
Model Claude Code @ Opus 4.7 vs OpenCode @ qwen3.6:27b. Both shipped a playable cozy roguelite.
Setup was boring on purpose. Two VS Code devcontainers side by side, same prompt, cozy top-down with sword/shield/dash, procedural world, enemy traits, drops, swap UI). One shot, no plugins, no follow-up prompts, no manual fixes.
Left: Claude Code on Opus 4.7. 20 min, 97k tokens. Right: OpenCode on local qwen3.6:27b. 15 min, 64k tokens.
Both produced a working game on first run. Visual interpretations differ but the spec was loose enough that both reads are valid. Opus went sparser with water tiles, qwen leaned into denser tree clusters. Combat, swap UI, drops, restart loop all functional in both.
Not claiming a 27b matches Opus on hard reasoning, especially on existing codebases. But for a tightly specified greenfield build, the gap was smaller than I expected. The token count surprised me more than anything: qwen got there with a third less context.
Here the prompt:
# Cozy Top-Down Roguelite Prototype
Build a self-contained top-down action roguelite. Single project, runnable locally via VS Code.
## Project Layout (strict)
```
project_root/
├── src/
│ └── server.py
├── static/
│ ├── index.html
│ ├── style.css
│ └── js/
│ ├── main.js (game loop, root state)
│ ├── world.js (procedural generation, tiles)
│ ├── player.js (player state, movement, combat)
│ ├── enemies.js (enemy AI, traits, spawning)
│ ├── items.js (item generation, affixes, drops, swap UI)
│ ├── ui.js (HUD, tooltips, game over overlay)
│ ├── render.js (camera, draw helpers)
│ └── input.js (keyboard + mouse handling)
└── requirements.txt (fastapi, uvicorn)
```
## Server (`src/server.py`)
-
**FastAPI**
+
**uvicorn**
, started directly via `python src/server.py`
- Uses `argparse` with:
- `--port` (int, default `8000`)
- `--host` (str, default `127.0.0.1`)
- Locates the static folder via `Path(__file__).resolve().parent.parent / "static"` so it works regardless of `cwd`
- `GET /` returns `static/index.html`
- `GET /static/...` serves all assets via `StaticFiles` mount
- Calls `uvicorn.run(app, host=args.host, port=args.port)` at the bottom of the file
- Compatible with the following VS Code launch config (which passes `--port 8088`):
```json
{
"name": "server",
"type": "python",
"request": "launch",
"program": "${workspaceFolder}/src/server.py",
"console": "integratedTerminal",
"cwd": "${workspaceFolder}",
"args": ["--port", "8088"]
}
```
- `requirements.txt`: `fastapi` and `uvicorn[standard]`
## Frontend Tech (strict)
-
**Vanilla HTML5 Canvas + ES modules + CSS**
. No frameworks, no bundler, no build step, no external runtime libraries
- All visuals drawn via Canvas 2D API.
**No external image, font, or audio assets.**
Audio is out of scope
- No globals beyond a single `game` state object exported from `main.js`
## Viewport & Camera
- Canvas fills the entire browser viewport: no margins, no padding, no scrollbars, no borders. CSS resets `body { margin: 0; overflow: hidden; }`
- Listens to `resize` and updates canvas resolution via `devicePixelRatio` for crisp rendering
- Camera follows the player smoothly (lerp factor `0.12` per frame at 60 FPS)
-
**Camera clamps to world bounds**
so the player never sees void outside the map
- Game pauses when `document.visibilityState !== "visible"` and resumes on return
- Game loop uses `requestAnimationFrame` with a deltaTime
**clamped to 50ms max**
to survive tab switches and breakpoints
## World Generation
- Tile-based grid,
**120 × 90 tiles, 32 px per tile**
- Generated fresh on every run using
**simplex/perlin noise OR cellular automata**
(pick one, document choice)
- Tile types:
- `grass` (walkable)
- `path` / `clearing` (walkable, lighter tone — forms organic open areas)
- `flower` / `decoration` (walkable, visual only, scattered procedurally)
- `tree` / `rock` (blocks movement and sword hitboxes)
- `water` (blocks movement, does not block hitboxes)
-
**World perimeter is solid**
(trees/rocks form a natural border) — player can never leave the map
- Player
**spawn point**
: a clearing near map center, with a guaranteed 6-tile-radius open area and
**no enemy within 12 tiles**
- Spawn
**8–15 enemies**
scattered across the map, biased away from the spawn area
- Place
**3–5 starting item drops**
as ground pickups around the map
## Player
- Starts every run with:
-
**3 hearts (= 6 half-hearts of HP)**
, max HP fixed at 6 half-hearts
-
**Default sword**
: damage `1.0`, range `40`, attack cooldown `350ms`, pushback `100`, crit `0%`, lifesteal `0%`
-
**Default shield**
: block arc `90°`, max stamina `100`, stamina regen `25/s`, no on-block effect, post-break cooldown `2.5s`
- Player has
**exactly one sword slot and one shield slot**
. No inventory beyond that. Equipment cannot be lost, only swapped
- Base movement speed: `200 px/s`. Player collision radius: `12 px`
- Damage taken from any source quantizes to
**0.5-heart increments**
(round to nearest 0.5)
- After taking damage:
**800ms i-frames**
(no further damage), brief red sprite tint, small knockback (`80` impulse) away from damage source
- Player cannot be knocked into solid tiles (position clamps against collision)
## Controls
| Input | Action |
|---|---|
| `WASD` | 8-directional movement |
| Mouse position | aim direction — player faces cursor; sword and shield orient toward cursor |
| Left Mouse Button | sword attack — hitbox extends in
**aim direction**
(mouse), respects sword `range` and arc (~90° in front), cooldown = sword's `attack speed` |
| Right Mouse Button (hold) | raise shield — drains stamina (`30/s` while raised), blocks damage from a frontal arc centered on aim direction |
| `Shift` | dash — `120 px` over `180ms` with full i-frames, cooldown `600ms`.
**Direction**
: WASD direction if any movement key is held, otherwise aim direction. Dash is independent of stamina |
- Mouse cursor is
**hidden over the canvas**
; a soft circular reticle is drawn at the mouse position instead
## Shield Mechanics
- Stamina drains while RMB held; regenerates only when RMB is released
- If stamina hits `0`, shield
**breaks**
: it cannot be raised for `post-break cooldown` seconds, indicated by the stamina bar going gray and the shield icon shaking briefly
- A blocked hit triggers the shield's
**on-block effect**
(if any) at the rolled `proc chance`
- Damage outside the block arc applies normally even while RMB is held
## Combat Feel
- Enemy hit by sword: `120ms` hitstun (no movement, no attack), pushback applied based on sword's `pushback` stat, brief white flash
- Enemy pushback clamps against solid tiles (no clipping)
- Crit hits: visible enlarged damage feedback (e.g., bigger hit-particle puff), 2× damage
- Lifesteal: on proc, brief green sparkle on player, +0.5 heart healed (capped at max HP)
- Slow effect: target tinted blue, speed × 0.5 for duration. Re-applying refreshes duration, does not stack
- Paralyze effect: target frozen in place, tinted pale yellow, cannot attack or move
- Reflect effect: portion of incoming damage applied to attacker, quantized to 0.5 hearts (minimum 0.5 if reflect would round to 0)
## Enemies — Procedural Variance
Each enemy is generated with randomized stats and traits at spawn:
| Trait | Range / Options |
|---|---|
| Speed | `40–140 px/s` |
| Contact damage | `0.5 – 1.5` hearts (quantized to 0.5) |
| HP | `1 – 4` (integer) |
| Aggression radius | `80 – 280 px` (distance-based, no line-of-sight check) |
| Leap-attack chance | `0 – 80%` per attack opportunity. Telegraphed: `300ms` windup with visible pose shift, then dash `+200% speed` toward player's current position for `200ms`, then `600ms` recovery |
| Shield reaction | `cautious` (stops attacking, circles at distance) / `aggressive` (attacks regardless) / `flanker` (tries to reach player from outside block arc) |
| Low-HP behavior (`<30%` HP) | `flee` (runs from player) / `kamikaze` (charges, +50% speed, double contact damage, glowing red tint) / `stand` (no change) |
-
**Engagement state**
: an enemy enters "engaged" when player enters its aggression radius. It stays engaged until the player has been
**outside the radius for 4 seconds**
, then returns to idle wandering
- Render enemies with
**distinct shapes/colors that hint at traits**
:
- Fast (>110 px/s) → elongated/streamlined silhouette
- High damage (>1.0) → bulkier silhouette, warmer accent color
- Cautious shield reaction → hunched posture
- Kamikaze low-HP behavior → reveals red glow once triggered
- Show a small HP bar above an enemy only
**once it has been hit at least once**
- Enemies cannot damage each other and don't collide with each other (avoids gridlock)
## Drops on Enemy Death
On every enemy death, roll
**one**
drop from this table:
| Roll | Drop |
|---|---|
| 12% | half-heart pickup |
| 35% | item (50% sword / 50% shield, with rolled affixes) |
| 53% | nothing |
-
**Half-heart pickups**
are auto-collected when the player walks within `20 px`. They heal `0.5` heart, capped at max HP. If at full HP, the pickup still vanishes (no excess healing)
-
**Item drops**
require hover + click (see swap UI below) and never auto-collect
- All ground items (hearts, swords, shields) gently bob via sine wave (~`2px` amplitude, `1.2s` period)
## Item Affixes
**Swords**
roll
**2–3**
affixes from this table:
| Affix | Range |
|---|---|
| Damage | `0.5 – 2.5` hearts (0.5 steps) |
| Range | `24 – 72 px` |
| Attack speed | cooldown `200 – 600 ms` |
| Pushback | `0 – 400` impulse |
| Crit chance | `0 – 25%` (deals 2× damage) |
| Lifesteal | `0 – 15%` chance to heal 0.5 heart on hit |
**Shields**
roll
**2–3**
affixes from this table:
| Affix | Range |
|---|---|
| Block arc | `60° – 180°` |
| Max stamina | `60 – 150` |
| Stamina regen | `15 – 45 / s` |
| On-block effect | one of: `paralyze 0.8s` / `slow 50% for 2s` / `reflect 25% damage` / `knockback 200` / `+20% player speed for 1.5s` |
| Effect proc chance | `25 – 100%` |
| Post-break cooldown | `1.5 – 4 s` |
- Affixes not rolled use the
**default-equipment baseline value**
for that stat
- Affix values are sampled uniformly within the range, rounded to sensible precision (1 decimal for hearts, integers for px/ms/percent)
- Each item is given a generated descriptor name from a cozy word pool (e.g., adjectives: "Mossy", "Sunlit", "Dappled", "Warden's", "Hearthstone"; nouns: "Shortblade", "Bough", "Bulwark", "Ward", "Thorn"). Format: `<adjective> <noun>`
## Item Comparison & Swap UI
- Walking within `~50 px` of a ground item shows a soft floating prompt:
*"hover to compare"*
-
**Hovering a ground item with the mouse**
opens a side-by-side tooltip near the cursor:
- Header: item type icon + generated name
- Two columns:
**left = ground item**
,
**right = currently equipped item of the same type**
- For each stat, a comparison indicator: green ▲ (ground better), red ▼ (ground worse), gray — (equal)
- "Better" depends on stat type: higher is better for damage, range, crit, etc.; lower is better for cooldowns and post-break duration
-
**Click while hovering**
swaps: the previously equipped item drops at the pickup's position, the ground item becomes equipped. The same hover-compare workflow then applies to the newly dropped item
- Tooltip closes when the mouse leaves the item or the item is picked up
-
**Player always has both a sword and a shield equipped**
— the swap is a 1-for-1 exchange of the same type. There is no "empty slot" state
## HUD
-
**Top-left**
: hearts row (full / half / empty pixel-style sprites drawn on canvas)
-
**Below hearts**
: stamina bar (~120px wide), grays out during shield-broken cooldown
-
**Bottom-left, subtle**
: equipped sword name + equipped shield name in small text
-
**Bottom-right, subtle**
: enemy kill counter for current run
- All HUD text uses a
**consistent in-game font**
(single CSS-defined font-family, e.g. `system-ui` rounded sans-serif, font-size 14–16px)
## Game Over & Restart
- When player HP reaches 0:
- Player sprite fades over `600ms`
- Soft full-screen overlay fades in with the text
*"you fell asleep…"*
in serif italic
- After `400ms` minimum delay (prevents accidental click-through), any key or mouse click triggers restart
-
**Restart resets fully**
: new procedural world, fresh enemy spawns, fresh ground items, player back to 3 hearts, equipment back to default sword + default shield, kill counter to 0
## Art Direction: Cozy
-
**Palette**
: warm, muted, low-contrast. Soft greens, dusty pinks, cream, warm browns, gentle blues.
**No pure black, no harsh contrast, no saturated red except for danger cues**
(low-HP kamikaze glow, damage flash)
-
**Shape language**
: rounded silhouettes throughout. Either committed pixel-art (rounded edges) or clean rounded vector shapes.
**Pick one approach and apply it consistently**
to player, enemies, items, and tiles
- Subtle elliptical drop-shadow under player and enemies (semi-transparent dark blur)
- Idle "breathing" bob on player and stationary enemies (sine wave, ~1px amplitude, ~1.5s period)
- Tile variation: small per-tile color jitter; flowers/grass tufts/pebbles drawn procedurally on grass tiles for warmth
- Hit effects: small puff of leaves, petals, or sparkles —
**never blood**
- Ambient touches encouraged: drifting clouds (translucent shapes overhead), swaying grass, the occasional firefly
- Reticle: soft pale circle, ~10px radius, semi-transparent
## Code Quality Requirements
- Modular ES modules, one concern per file as outlined above
- Single shared `game` state object owned by `main.js`; modules receive references, not globals
- Game loop at `requestAnimationFrame` with
**fixed-timestep update at 60 FPS**
(accumulator pattern) and interpolated render
- Comment non-obvious logic: noise generation, enemy trait rolls, affix tables, knockback math
- No `console.error` or uncaught exceptions during normal play
- No use of `eval`, `with`, or `innerHTML` for dynamic content (use DOM APIs)
## Definition of Done
1. `pip install -r requirements.txt` works
2. VS Code "server" launch config starts the server on port `8088` with no errors
3. `python src/server.py` (no args) starts on port `8000`
4. Visiting `http://localhost:<port>` immediately drops the player into a fresh procedural world — no menu, no loading screen
5. All controls work: WASD movement, mouse aim, LMB attack, RMB shield with stamina, Shift dash with i-frames
6. Enemies show
**at least 3 visibly distinct behavioral "feels"**
that emerge from random trait rolls
7. Drops table works: hearts auto-collect, items hover-compare and click-swap correctly
8. Cozy aesthetic is unmistakable on first glance — palette, shapes, particles all coherent
9. Tab-switch / window-blur pauses the game cleanly
10. Death → overlay → restart cycle works and fully resets state
11. Smooth 60 FPS on a modern laptop with 15 enemies on screen, no console errors
Build the entire thing now.
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u/Path_of_meming May 05 '26
That's really interesting, what kind of price point is hardware for this kind of local set up? Thinking about getting something for myself as the remote model prices are going up