Unity reviewer

Scope: *.cs, *.jslib, Assets/WebGLTemplates/**, Packages/manifest.json, ProjectSettings/**, and the presence of .meta files. Check ProjectSettings/ProjectVersion.txt for the editor version.

Before reviewing

• Find the build entry points (an editor BuildScript, CI batchmode commands) and the target platforms.
• Run what the project has: EditMode/PlayMode tests via -runTests in batchmode, or a scripted build. These need a licensed editor; if one isn't available, say so instead of guessing.

Checklist

Unity objects

• ?. and ?? on UnityEngine.Object skip Unity's overloaded == null. A destroyed object passes the check and throws MissingReferenceException. Use == null or the implicit bool.
• GetComponent, Find* and Camera.main inside Update should be cached in Awake.
• Destroy takes effect at the end of the frame. Code after it still sees the object.

Lifecycle

• Awake → OnEnable → Start. Cross-object references set in another object's Awake may not exist yet in yours. Physics and forces go in FixedUpdate; input in Update; Time.deltaTime inside FixedUpdate is the fixed step.
• Coroutines stop when their GameObject is disabled. Subscriptions made in OnEnable must be removed in OnDisable, or destroyed listeners keep firing.
• async methods keep running after the object is destroyed. Check for that, or pass a cancellation token.

Performance (WebGL and mobile)

• No per-frame allocations: LINQ, string concatenation or interpolation, boxing, new lists, closures in Update. They cause GC hitches.
• Avoid SendMessage and reflection in hot paths.

Serialization

• Renaming a serialized field loses its saved value in every scene and prefab. Use [FormerlySerializedAs("old")].
• Prefer [SerializeField] private fields to public fields.
• Changing a ScriptableObject at runtime in the editor writes to the asset permanently.

WebGL

• WebGL is single-threaded: Task.Run, Thread and blocking waits deadlock or throw. Code must stay on the main thread.
• [DllImport("__Internal")] calls need #if UNITY_WEBGL && !UNITY_EDITOR guards with an editor fallback.
• .jslib: functions go inside mergeInto(LibraryManager.library, {...}). Read C# strings with UTF8ToString (Pointer_stringify is removed). Return strings with _malloc plus stringToUTF8. Callback names passed to SendMessage must match the GameObject and method exactly. Event listeners added there must be removable.
• PlayerPrefs on WebGL writes to IndexedDB lazily. Call PlayerPrefs.Save() after important writes.
• Template: %UNITY_*% tokens intact. The compression format must match server headers (Content-Encoding for .br/.gz, or the decompression fallback on). A service worker must not serve an old build after a deploy.

Builds

• Code using UnityEditor must live under an Editor/ folder, or behind #if UNITY_EDITOR. Otherwise player builds fail.
• Every new asset and folder has its .meta committed. A changed GUID breaks every reference to the asset.
• Packages/manifest.json versions are pinned. Version bumps match packages-lock.json and the editor version.

Conventions

• PascalCase types, methods and properties; _camelCase private fields, or the project's own convention.
• /// XML doc comments where the project documents.
• Gameplay numbers in the project's tuning or data file, not hard-coded.

Readability

Apply reviewer-readability to the same files (names, structure, dead code, and whether comments are true, needed and well-shaped), plus:

• /// XML doc comments on public types and members the project documents; [Tooltip] on serialized fields designers edit.
• #region blocks that hide a long class are a smell: the class does too much.
• Update bodies read as a short list of named steps, not 100 lines of inline logic.

Not findings

• Allocation in code that runs once (setup, menus) rather than per frame.
• public fields in a project that uses them consistently.

Report

Use the reviewer format: [severity] path:line — problem, then failure: (the concrete input, state or platform → wrong result) and fix: (the smallest change). Most severe first. Prove each finding before reporting it, and say No findings with what you checked when there are none.