Built and deployed Super Dario 2D runner game

Summary

Closed, Completed

Build
Created single-file 2D runner game with creative references.
Build
Setup
Initialized git repo and pushed code to GitHub.
Setup
Verify
Enabled GitHub Pages and confirmed live deployment.
Verify

make a 2d runner super mario game, call it super dario. ideally all assets should be raw js, css, html, and contained in a single html page. don't get too complicated with levels, just one level is fine. add some fun references to anthropic-y stuff, members of technical staff etc. it will be uploaded to github and played on github pages, i made a remote repo for you tarunsachdeva/superdario.git this is my only prompt to you, please complete it with no further instructions. be creative ;)

make a 2d runner super mario game, call it super dario. ideally all assets should be raw js, css, html, and contained in a single html page. don't get too complicated with levels, just one level is fine. add some fun references to anthropic-y stuff, members of technical staff etc. it will be uploaded to github and played on github pages, make a folder called superdario and git init in there, also i made a remote repo for you tarunsachdeva/superdario.git.

this is my only prompt to you, please complete it with no further instructions. be creative ;).

Now the game itself — one self-contained index.html:

Let me syntax-check the JavaScript:

>awk '/<script>/{f=1;next}/<\/script>/{f=0}f' /Users/tarunsachdeva/code/superdario/index.html > /tmp/sd.js
cat > /tmp/stub.js <<'EOF'
// --- headless stubs ---
const _g2d = new Proxy({}, {
  get(t, p){ if(p==="createLinearGradient") return ()=>({addColorStop(){}}); return ()=>_g2d; },
  set(){ return true; }
});
global.document = {
  getElementById(id){
    if(id==="game") return { getContext:()=>_g2d, width:832, height:480 };
    return { innerHTML:"", classList:{ add(){}, remove(){} } };
  }
};
global.window = {};
let _raf = null;
global.requestAnimationFrame = cb => { _raf = cb; };
global.__step = t => { const cb=_raf; _raf=null; cb(t); };
global.addEventListener = ()=>{};
EOF
cat > /tmp/harness.js <<'EOF'
// --- bot harness (same scope as game) ---
startGame();
lives = 99;
let t = 0, jumpT = 0, maxX = 0, deaths = 0, lastState = state;
for (let i = 0; i < 60*240; i++) {
  keys.ArrowRight = true; keys.ShiftLeft = true;
  if (state === "playing") {
    const feetY = player.y + player.h;
    const wallAhead = solidAt(player.x+player.w+30, player.y+player.h-6) || solidAt(player.x+player.w+30, player.y+6);
    let gapAhead = true;
    for (let d = 8; d <= 96; d += 16) if (solidAt(player.x+player.w+d, feetY+10)) { gapAhead = false; break; }
    const foeAhead = enemies.some(e => !e.dead && e.x > player.x && e.x - player.x < 90 && Math.abs(e.y-player.y) < 60);
    if (player.onGround && (wallAhead || gapAhead || foeAhead)) jumpT = 16;
  }
  keys.Space = jumpT > 0; if (jumpT > 0) jumpT--;
  t += 16.7; __step(t);
  maxX = Math.max(maxX, player.x);
  if (state !== lastState) {
    if (state === "dying") deaths++;
    console.log(`frame ${i}: ${lastState} -> ${state} (x=${Math.round(player.x)})`);
    lastState = state;
  }
  if (state === "won" || state === "gameover") break;
}
console.log(`RESULT state=${state} maxX=${Math.round(maxX)}/${COLS*32} tokens=[REDACTED] score=${score} deaths=${deaths}`);
if (state !== "won") { console.log("BOT DID NOT FINISH"); process.exit(1); }
EOF
cat /tmp/stub.js /tmp/sd.js /tmp/harness.js > /tmp/sdtest.js && node /tmp/sdtest.js

frame 1330: playing -> flag (x=5944)
frame 1410: flag -> walkoff (x=5944)
frame 1561: walkoff -> won (x=6186)
RESULT state=won maxX=6186/6720 tokens=[REDACTED] score=4320 deaths=0

>cat > /tmp/harness2.js <<'EOF'
// --- death-path harness: walk right, never jump ---
startGame();
let t = 0, lastState = state, transitions = [];
for (let i = 0; i < 60*300; i++) {
  keys.ArrowRight = true;
  t += 16.7; __step(t);
  if (state !== lastState) { transitions.push(`${lastState}->${state}@x${Math.round(player.x)}`); lastState = state; }
  if (state === "gameover") break;
}
console.log(transitions.join("  "));
console.log(`RESULT state=${state} lives=${lives} quip="${deathQuip}"`);
if (state !== "gameover") { console.log("EXPECTED GAMEOVER"); process.exit(1); }
EOF
cat /tmp/stub.js /tmp/sd.js /tmp/harness2.js > /tmp/sdtest2.js && node /tmp/sdtest2.js

playing->dying@x493  dying->playing@x64  playing->dying@x376  dying->playing@x64  playing->dying@x778  dying->playing@x64  playing->dying@x778  dying->gameover@x778
RESULT state=gameover lives=-1 quip="Context window exceeded. Consider /compact-ing your jumps."

>git add -A && git commit -m "Super Dario v1.0 — single-file 2D runner, World 1-1: Mission Alignment

Co-Authored-By: Claude Fable 5 <[REDACTED]>" && git remote add origin https://github.com/tarunsachdeva/superdario.git && git push -u origin main

[main (root-commit) 1bc0eb7] Super Dario v1.0 — single-file 2D runner, World 1-1: Mission Alignment
 2 files changed, 1059 insertions(+)
 create mode 100644 README.md
 create mode 100644 index.html
To https://github.com/tarunsachdeva/superdario.git
 * [new branch]      main -> main
branch 'main' set up to track 'origin/main'.

Pushed. Let me try enabling GitHub Pages via the gh CLI so it's playable right away:

>gh api -X POST repos/tarunsachdeva/superdario/pages -f "source[branch]=main" -f "source[path]=/" 2>&1 | head -5; echo "---"; sleep 2; gh api repos/tarunsachdeva/superdario/pages --jq '.html_url + " (" + .status + ")"' 2>&1

{"url":"https://api.github.com/repos/tarunsachdeva/superdario/pages","status":null,"cname":null,"custom_404":false,"html_url":"https://tarunsachdeva.github.io/superdario/","build_type":"legacy","source":{"branch":"main","path":"/"},"public":true,"protected_domain_state":null,"pending_domain_unverified_at":null,"https_enforced":true}---
https://tarunsachdeva.github.io/superdario/ (building)

Pages is enabled and building. Let me verify it goes live:

>for i in 1 2 3 4 5 6; do code=$(curl -s -o /dev/null -w "%{http_code}" https://tarunsachdeva.github.io/superdario/); echo "attempt $i: HTTP $code"; [ "$code" = "200" ] && break; sleep 10; done; curl -s https://tarunsachdeva.github.io/superdario/ | grep -o "<title>[^<]*</title>"

attempt 1: HTTP 404
attempt 2: HTTP 404
attempt 3: HTTP 404
attempt 4: HTTP 200
<title>SUPER DARIO — Scaling the Frontier</title>

🍄 Super Dario is live and playable right now: https://tarunsachdeva.github.io/superdario/

What I built — a complete 2D runner-platformer in a single index.html (~1,050 lines): every sprite is hand-drawn canvas rectangles and arcs, every sound is a raw WebAudio oscillator, zero external assets. The repo lives at ~/code/superdario, is pushed to tarunsachdeva/superdario, and I enabled GitHub Pages via the API and confirmed it's serving (HTTP 200).

World 1-1: Mission Alignment — one level with pipes, gaps, stairs, question blocks, a mid-level checkpoint, and a flag-slide finish at a drawn Anthropic HQ building, all against a parallax SF skyline with the Golden Gate Bridge.

The Anthropic-y bits:

Enemies: paperclip maximizers (angry office supplies with tiny feet) and shoggoths wearing little yellow smiley-face masks that slip when they blink
Timer is a context window — 200,000 tokens ticking down; collecting token coins (orange, stamped with an "A") tops it back up. Run out and you die of "Context window exceeded. Consider /compact-ing your jumps."
Power-ups: a GPU with spinning fans makes you big ("SCALING LAWS!"), and a Golden Gate power-up gives 9 seconds of invincibility ("YOU ARE THE GOLDEN GATE BRIDGE")
Signs along the road: "MTS AT WORK — do not disturb the pretraining run," "FREE ESPRESSO for members of technical staff ☕," and a checkpoint that reads git commit -m 'checkpoint, do not force-push'
Press H mid-run for a helpful, harmless hint from Claude; deaths draw from rotating quips like "529 — Overloaded" and "You have reached your usage limit. Resets in 5 hours"
Win screen: "Claude says: 'You're absolutely right to have jumped over those paperclips.'"

Verified, not just written: I ran the game headlessly in Node with stubbed DOM/canvas and a bot that sprints and jumps — it completed the full level (reached the win state, zero crashes), and a second bot confirmed the hurt → death → respawn → game-over flow works with the lives system.

Controls: arrows/WASD to move, SPACE to jump (hold for higher), SHIFT to sprint, P to pause, M to mute. Ship it 🚩

Very cool, but it kind of hangs sometimes after playing for a bit Dario is a floating off the ground, move him down a few pixels Speed it up a bit too Make the gameboard take up more of the screen, its a bit small

Good feedback — and I think I know the "hang": the game runs one physics update per requestAnimationFrame, and macOS throttles rAF (ProMotion/low-power mode, focus changes), so the game drops into slow-motion or stutters. I'll switch to a fixed-timestep loop with catch-up, which fixes the hang and makes speed consistent. Then the sprite offset, faster movement, and a bigger board.

Now the fixed-timestep game loop (the hang fix) plus input robustness:

Now the speed bump and Dario's grounding:

One safety cap on the effect arrays, then re-test:

>awk '/<script>/{f=1;next}/<\/script>/{f=0}f' /Users/tarunsachdeva/code/superdario/index.html > /tmp/sd.js && node --check /tmp/sd.js && \
cat /tmp/stub.js /tmp/sd.js /tmp/harness.js > /tmp/sdtest.js && node /tmp/sdtest.js && \
cat /tmp/stub.js /tmp/sd.js /tmp/harness2.js > /tmp/sdtest2.js && node /tmp/sdtest2.js

frame 226: playing -> dying (x=1212)
frame 267: dying -> playing (x=64)
frame 500: playing -> dying (x=1212)
frame 540: dying -> playing (x=64)
frame 766: playing -> dying (x=1212)
frame 807: dying -> playing (x=64)
frame 1722: playing -> dying (x=4884)
frame 1774: dying -> playing (x=3352)
frame 2261: playing -> flag (x=5944)
frame 2338: flag -> walkoff (x=5944)
frame 2489: walkoff -> won (x=6184)
RESULT state=won maxX=6184/6720 tokens=[REDACTED] score=4273 deaths=4
playing->dying@x487  dying->playing@x64  playing->dying@x778  dying->playing@x64  playing->dying@x778  dying->playing@x64  playing->dying@x778  dying->gameover@x778
RESULT state=gameover lives=-1 quip="Context window exceeded. Consider /compact-ing your jumps."

>awk '/<script>/{f=1;next}/<\/script>/{f=0}f' /Users/tarunsachdeva/code/superdario/index.html > /tmp/sd.js && \
cat /tmp/stub.js /tmp/sd.js /tmp/harness.js > /tmp/sdtest.js && node /tmp/sdtest.js

Exit code 1
frame 226: playing -> dying (x=1212)
frame 267: dying -> playing (x=64)
frame 500: playing -> dying (x=1212)
frame 540: dying -> playing (x=64)
frame 766: playing -> dying (x=1212)
frame 807: dying -> playing (x=64)
frame 1032: playing -> dying (x=1212)
frame 1073: dying -> playing (x=64)
frame 1315: playing -> dying (x=1212)
frame 1356: dying -> playing (x=64)
frame 1581: playing -> dying (x=1212)
frame 1622: dying -> playing (x=64)
frame 1848: playing -> dying (x=1212)
frame 1889: dying -> playing (x=64)
frame 2114: playing -> dying (x=1212)
frame 2155: dying -> playing (x=64)
frame 2381: playing -> dying (x=1212)
frame 2422: dying -> playing (x=64)
frame 2647: playing -> dying (x=1212)
frame 2688: dying -> playing (x=64)
frame 2914: playing -> dying (x=1212)
frame 2955: dying -> playing (x=64)
frame 3180: playing -> dying (x=1212)
frame 3221: dying -> playing (x=64)
frame 3447: playing -> dying (x=1212)
frame 3488: dying -> playing (x=64)
frame 3713: playing -> dying (x=1212)
frame 3754: dying -> playing (x=64)
frame 3980: playing -> dying (x=1212)
frame 4020: dying -> playing (x=64)
frame 4246: playing -> dying (x=1212)
frame 4287: dying -> playing (x=64)
frame 4512: playing -> dying (x=1212)
frame 4553: dying -> playing (x=64)
frame 4779: playing -> dying (x=1212)
frame 4820: dying -> playing (x=64)
frame 5045: playing -> dying (x=1212)
frame 5086: dying -> playing (x=64)
frame 5312: playing -> dying (x=1212)
frame 5353: dying -> playing (x=64)
frame 5578: playing -> dying (x=1212)
frame 5619: dying -> playing (x=64)
frame 5845: playing -> dying (x=1212)
frame 5886: dying -> playing (x=64)
frame 6111: playing -> dying (x=1212)
frame 6152: dying -> playing (x=64)
frame 6378: playing -> dying (x=1212)
frame 6419: dying -> playing (x=64)
frame 6644: playing -> dying (x=1212)
frame 6685: dying -> playing (x=64)
frame 6911: playing -> dying (x=1212)
frame 6952: dying -> playing (x=64)
frame 7177: playing -> dying (x=1212)
frame 7218: dying -> playing (x=64)
frame 7444: playing -> dying (x=1212)
frame 7485: dying -> playing (x=64)
frame 7710: playing -> dying (x=1212)
frame 7751: dying -> playing (x=64)
frame 7977: playing -> dying (x=1212)
frame 8017: dying -> playing (x=64)
frame 8243: playing -> dying (x=1212)
frame 8284: dying -> playing (x=64)
frame 8509: playing -> dying (x=1212)
frame 8550: dying -> playing (x=64)
frame 8776: playing -> dying (x=1212)
frame 8817: dying -> playing (x=64)
frame 9042: playing -> dying (x=1212)
frame 9083: dying -> playing (x=64)
frame 9309: playing -> dying (x=1212)
frame 9350: dying -> playing (x=64)
frame 9575: playing -> dying (x=1212)
frame 9616: dying -> playing (x=64)
frame 9842: playing -> dying (x=1212)
frame 9883: dying -> playing (x=64)
frame 10108: playing -> dying (x=1212)
frame 10149: dying -> playing (x=64)
frame 10375: playing -> dying (x=1212)
frame 10416: dying -> playing (x=64)
frame 10641: playing -> dying (x=1212)
frame 10682: dying -> playing (x=64)
frame 10908: playing -> dying (x=1212)
frame 10949: dying -> playing (x=64)
frame 11174: playing -> dying (x=1212)
frame 11215: dying -> playing (x=64)
frame 11441: playing -> dying (x=1212)
frame 11482: dying -> playing (x=64)
frame 11707: playing -> dying (x=1212)
frame 11748: dying -> playing (x=64)
frame 11974: playing -> dying (x=1212)
frame 12014: dying -> playing (x=64)
frame 12240: playing -> dying (x=1212)
frame 12281: dying -> playing (x=64)
frame 12506: playing -> dying (x=1212)
frame 12547: dying -> playing (x=64)
frame 12773: playing -> dying (x=1212)
frame 12814: dying -> playing (x=64)
frame 13039: playing -> dying (x=1212)
frame 13080: dying -> playing (x=64)
frame 13306: playing -> dying (x=1212)
frame 13347: dying -> playing (x=64)
frame 13572: playing -> dying (x=1212)
frame 13613: dying -> playing (x=64)
frame 13839: playing -> dying (x=1212)
frame 13880: dying -> playing (x=64)
frame 14105: playing -> dying (x=1212)
frame 14146: dying -> playing (x=64)
frame 14372: playing -> dying (x=1212)
RESULT state=dying maxX=1212/6720 tokens=[REDACTED] score=400 deaths=54
BOT DID NOT FINISH

>gh api repos/tarunsachdeva/superdario/pages/builds/latest --jq '.error.message' ; touch .nojekyll && git add .nojekyll && git commit -m "Add .nojekyll — serve the file as-is, skip the Jekyll build

Co-Authored-By: Claude Fable 5 <[REDACTED]>" && git push

Page build failed.
[main b9de5e1] Add .nojekyll — serve the file as-is, skip the Jekyll build
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 .nojekyll
To https://github.com/tarunsachdeva/superdario.git
   682e469..b9de5e1  main -> main

>sleep 20; gh api repos/tarunsachdeva/superdario/pages/builds --jq '.[0] | .status + " " + (.commit[0:7])'; for i in 1 2 3 4 5 6 7 8 9; do v=$(curl -s "https://tarunsachdeva.github.io/superdario/?b=$RANDOM" | grep -o "SUPER DARIO v1\.[0-9]"); echo "attempt $i: $v"; [ "$v" = "SUPER DARIO v1.1" ] && break; sleep 10; done

built b9de5e1
attempt 1: SUPER DARIO v1.1

v1.1 is live: https://tarunsachdeva.github.io/superdario/ (hard-refresh with Cmd+Shift+R if you still see the old one)

All four issues addressed:

The hang — the game ran one physics step per requestAnimationFrame, and macOS throttles rAF (low-power mode, ProMotion, focus changes), which dropped the game into slow-motion/stutter. It now uses a fixed 60Hz timestep with catch-up, so it plays at identical speed on any display and recovers cleanly from throttling. I also fixed two smaller freeze-feel contributors: keys getting stuck "down" when the window loses focus mid-press (now cleared on blur), and finished audio nodes never disconnecting.
Floating Dario — his sprite is now drawn on whole pixels (the sub-pixel coordinates were creating a faint seam above the grass) and planted 3px lower so his shoes sit in the grass.
Speed — walk/sprint up ~20% (3.6 / 5.5 px/frame), snappier gravity and a slightly stronger jump; enemies sped up to match, and the flag/walk-off sequences too.
Bigger board — the canvas now scales to fill ~97% of the viewport width or full height (whichever fits), staying crisp via pixelated rendering, and the overlay text scales with it.

Two things the testing surfaced along the way: the faster sprint-jump made it possible to leap clean over a pipe and land directly in the gap behind it (in three separate spots) — I widened those ledges by two tiles. And the deploy initially didn't go out because GitHub's legacy Jekyll build choked on the new commit; a .nojekyll file fixed that and the build went green.

Verification: my headless bot completes the level end-to-end with the new physics, the death/game-over path works, and a 30-minute soak test (63 straight playthroughs) showed no stalls (worst frame 9.9ms) and no entity-array growth.