In Windows and MacOS, pretty straightforward.

For Ubuntu 24.04, will need to run the Unity Hub binary in unconfined mode (trust them...?):

# Install instructions: https://docs.unity3d.com/hub/manual/InstallHub.html#install-hub-linux
# Add signing key
user:~$ wget -qO - https://hub.unity3d.com/linux/keys/public | gpg --dearmor | sudo tee /usr/share/keyrings/Unity_Technologies_ApS.gpg > /dev/null
# Add repository
user:~$ sudo sh -c 'echo "deb [signed-by=/usr/share/keyrings/Unity_Technologies_ApS.gpg] https://hub.unity3d.com/linux/repos/deb stable main" > /etc/apt/sources.list.d/unityhub.list'
# Install
user:~$ sudo apt update && sudo apt install unityhub
 
# Run in unconfined mode, otherwise will fail to start
# See: https://discussions.unity.com/t/unity-hub-and-x-ubuntu-24-04-not-starting-workaround/945633
user:~$ cat /etc/apparmor.d/unityhub
abi <abi/4.0>,
include <tunables/global>
profile unityhub /opt/unityhub/unityhub-bin flags=(unconfined) {
userns,
# Site-specific additions and overrides. See local/README for details.
include if exists <local/unityhub>
}
user:~$ sudo systemctl restart apparmor.service

### Unity ###
# This .gitignore file should be placed at the root of your Unity project directory
#
# Get latest from https://github.com/github/gitignore/blob/main/Unity.gitignore
/[Ll]ibrary/
/[Tt]emp/
/[Oo]bj/
/[Bb]uild/
/[Bb]uilds/
/[Ll]ogs/
/[Uu]ser[Ss]ettings/
 
# MemoryCaptures can get excessive in size.
# They also could contain extremely sensitive data
/[Mm]emoryCaptures/
 
# Recordings can get excessive in size
/[Rr]ecordings/
 
# Uncomment this line if you wish to ignore the asset store tools plugin
# /[Aa]ssets/AssetStoreTools*
 
# Autogenerated Jetbrains Rider plugin
/[Aa]ssets/Plugins/Editor/JetBrains*
 
# Visual Studio cache directory
.vs/
.vscode/
.vsconfig
 
# IntelliJ
.idea/
 
# Temporary Files
Temp/
/Temp/
 
# Gradle cache directory
.gradle/
 
# Autogenerated VS/MD/Consulo solution and project files
ExportedObj/
.consulo/
*.csproj
*.unityproj
*.sln
*.suo
*.tmp
*.user
*.userprefs
*.pidb
*.booproj
*.svd
*.pdb
*.mdb
*.opendb
*.VC.db
 
# Unity3D generated meta files
*.pidb.meta
*.pdb.meta
*.mdb.meta
 
# Unity3D generated file on crash reports
sysinfo.txt
 
# Builds
*.apk
*.aab
*.unitypackage
*.app
 
# Crashlytics generated file
crashlytics-build.properties
 
# Packed Addressables
/[Aa]ssets/[Aa]ddressable[Aa]ssets[Dd]ata/*/*.bin*
 
# Temporary auto-generated Android Assets
/[Aa]ssets/[Ss]treamingAssets/aa.meta
/[Aa]ssets/[Ss]treamingAssets/aa/*
 
# Never ignore DLLs in the FMOD subfolder.
!/[Aa]ssets/Plugins/FMOD/**/lib/*
 
# Don't ignore images and gizmos used by FMOD in the Unity Editor.
!/[Aa]ssets/Gizmos/FMOD/*
!/[Aa]ssets/Editor Default Resources/FMOD/*
 
# Ignore the Cache folder since it is updated locally.
/[Aa]ssets/Plugins/FMOD/Cache/*
 
# Ignore bank files in the StreamingAssets folder.
/[Aa]ssets/StreamingAssets/**/*.bank
/[Aa]ssets/StreamingAssets/**/*.bank.meta
 
# If the source bank files are kept outside of the StreamingAssets folder then these can be ignored.
# Log files can be ignored.
fmod_editor.log
 
# Ignore FMOD plugin build settings across workstations
[Aa]ssets/Plugins/FMOD/Resources/FMODStudioSettings.asset

using UnityEngine;
 
public class FireballMovement : MonoBehaviour
{
    private Rigidbody2D rb;
    public float fallSpeed = 20f;
    public float despawnMargin = 0.5f;
    private float destroyHeight;
 
    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
        destroyHeight = -Camera.main.orthographicSize - despawnMargin;
    }
 
    private void FixedUpdate()
    {
        rb.MovePosition(rb.position + Vector2.down * fallSpeed * Time.fixedDeltaTime);
        if (rb.position.y < destroyHeight) {
            Destroy(gameObject);
        }
    }
 
    // Affect the score in the statemanager
    private void OnTriggerEnter2D(Collider2D other)
    {
        if (other.CompareTag("Player")) {
            PersistentState.state.GetScoreManager()
                .SetIncrement(scoreKey);
        }
    }
}

using UnityEngine;
 
public class DelayedActivation : MonoBehaviour
{
    public float delayTime = 1f;
    private float elapsedTime = 0.0f;
 
    void FixedUpdate()
    {
        elapsedTime += Time.deltaTime;
        if (elapsedTime >= delayTime) {
            foreach (Transform child in transform)
                child.gameObject.SetActive(true);
        }
    }
}

using System.Collections;
using UnityEngine;
 
 
public class TimedTransition : MonoBehaviour
{
    public string nextSceneName;  // Set the next scene's name in the Unity Inspector
    public float waitDuration = 5f;
 
    void Start()
    {
        StartCoroutine(WaitAndLoadScene());
    }
 
    IEnumerator WaitAndLoadScene()
    {
        yield return new WaitForSeconds(waitDuration);  // Wait for 5 seconds
        Initiate.Fade(nextSceneName, Color.black, 1);
    }
}

using System;
using UnityEngine;
 
public class PersistentState : MonoBehaviour
{
    public static PersistentState state;
    private MusicManager music;  // or use arrays to manage concurrent
 
    void Awake()
    {
        if (state != null && state != this) {
            Destroy(this.gameObject);
            return;
        }
        DontDestroyOnLoad(this.gameObject);
        state = this;
 
        // Bootstrap
        music = GetComponent<MusicManager>();
    }
    public MusicManager GetMusicManager() {
        return music;
    }
}

Shot lists with individual scene numbers for easier reference, a sketch of the visuals, description of expected gameplay:

Art asset lists for tracking of assets available for integration. Recommended to generate quick sprites for backgrounds and character sprites for programmers to use as placeholders (which can then be asynchronously updated by the developers). Need to factor in creation of spritesheets for eventual animations as well, and marketing material.

Music asset list for tracking of music assets as well. For tracks with more involved automation/parameter controls, placeholders should be created early on as well. Art to provide music team with initial concept art for tailoring music. Note there needs to be tighter communication especially if using video/animation requiring SFX/music integration.

Code repository should be as neatly organized as possible, with logical groupings for scripts, and clear scene naming according to the game design specifications:

using System;
using UnityEngine;
 
public class MusicManager : MonoBehaviour
{
    public FMODUnity.EventReference music;
    private FMOD.Studio.EventInstance instance;
 
    void Awake() {
        Load(music);
    }
    void OnDestroy() {
        Unload();
    }
 
    public void Reload(FMODUnity.EventReference other) {
        if (other.Guid == music.Guid) return;
        Unload();
        Load(other);
    }
    void Load(FMODUnity.EventReference other) {
        music = other;
        instance = FMODUnity.RuntimeManager.CreateInstance(music);
    }
    void Unload() {
        instance.release();
    }
 
    public void Play() {
        if (IsPlaying()) return;
        instance.start();
    }
    public void Stop() {
        instance.stop(FMOD.Studio.STOP_MODE.ALLOWFADEOUT);
    }
    public bool IsPlaying() {
        // Note this is conceptually different from PLAYBACK_STATE.PLAYING
        FMOD.Studio.PLAYBACK_STATE playbackState;
        instance.getPlaybackState(out playbackState);
        return playbackState != FMOD.Studio.PLAYBACK_STATE.STOPPED;
    }
    public void SetParameter(string name, int value, bool play = false) {
        instance.setParameterByName(name, value);
        if (play) Play();
    }
}