Built and deployed Super Dario 2D runner gamePublic

Agent

Claude Code

Model

Claude Fable 5

Shared

Jul 7, 10:13 PM

Messages75

Downloads2

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:

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

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

🍄 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:

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.