What problem does it solve? Runtime slowdowns, stutter, and jumpy movement in browser games are hard to root-cause because symptoms like frame hitches can come from simulation backlog, render growth, memory leaks, or storage stalls. This Skill provides a measurement-first workflow that isolates the actual failure bucket before any code is edited. ## Core Features & Use Cases - Measurement-First Diagnosis: Add temporary page-side probes with page.evaluate to capture scene children counts, pool lengths, world entity arrays, snapshot sizes, and timed calls around world.tick and persistence. - Fixed-Step Accumulator Analysis: Inspect frame delta clamping and MAX_SUBSTEPS backlog handling to find stale accumulator debt that causes jumpy movement after hitches, tab refocus, or GC pauses. - Regression Test Workflow: Build focused mechanical regressions (e.g., feeding repeated long deltaMs values) and red/green them by reverting the fix to confirm the test fails for the intended reason. - Use Case: A Phaser game gets progressively jumpier during long play sessions. Use this Skill to prove object counts stay flat, identify stale accumulator backlog as the root cause, and ship a fix with a stable regression test. ## Quick Start Use the debugging-performance-issues skill to diagnose why the game stutters and gets slower over long play sessions.
