1) Career mode: start from a single prop 2nd officer as you climb the ranks.
2) Pax and crew animation
3) Virtual Airlines Module on multi-player: In-game module where you can create or join a virtual airline company with an inbuilt company management system.
4) Aircraft Maintenance Logging: Let's say you fly an aircraft everyday but you fly rough, the aircraft saves it's last damage state no matter how minimal. Over time the aircraft may develop problems mid flight if you don't do checks and take it to the maintenance hangar.
Goodluck Microsoft, we routing for your success with this one.