Grateful thanks to Freesounders leuphana, nathan-lomeli, samararaine, medialint, lebcraftlp, hunter4708. Thanks also to the makers of Blender and MuseScore.
Scroll map - Up and down arrow keys
Build - click to move the build cursor, choose a tunnel from the Build Tunnel menu or use hotkeys: C=coridoor E=elevator V=clone-vat O=office L=life support
Assign Roles - choose a Faction from the Faction-Role menu, then choose a Role to assign to that faction: Construction, Repair, Paperwork or Firefighting. For example if you choose Hufflepuffs and Paperwork then all Hufflepuffs will be assigned to do Paperwork whenever they are near an Office. At the start, all Factions are assigned to Construction.
Clonevats produce cloned citizens. Offices make money through Paperwork. Life Support produces food/oxygen/water for 10 citizens. When these tunnels break down, assign a Faction to the Repair role.
Increase the population of the Citadel to 150 to win. Keep your citizens occupied to prevent boredom - bored citizens will start to light fires or try to break out of the Citadel. You can turn the music score on and off by clicking the music button. Hint: it's not a bad idea to start by building an Office then assigning one Faction to Paperwork.