Building a complex system (computer, car, boat) from hardware parts requires knowledge of constraints, synergies, and co-requirements.
Theme: you own a shop where customers want to buy a system with particular features (eg computer with latest graphics card or low power consumption).
Core loop: optimize a build by selecting the best/cheapest parts that synergize well. Like http://pcpartpicker.com. Could add an auction house to it. Buy/trade/sell parts, dismantle systems to get parts, dismantle parts like CPU to get materials like screws or silicon. Higher skill gives more yield.
Long loop: make profits from selling systems, unlock new parts from manufacturers, gain a customer rep (eg super cheap but often breaks, great customer service but overpriced), and gain manufacturer rep (sell Nvidia and AMD won't talk to you).
Placing various parts on a motherboard: