This game is rated ESRB: Everyone.
Heidi-Express is an add-on for Microsoft Train Simulator which adds tracks and landscape along the Swiss Alps. The Rhätische Bahn rail line, which operate in this area are represented, and this add-on carries their license. This add-on adds 20 new stations and mountainous landscape between them. Also included is a variety of rolling stock (passenger cars, frieght cars, box cars, etc) used on the route as well as three new engines: The Ge 4/4 II Trilfahrzeug, The Ge 4/4 III Schnellzuglok and the Ge 6/6 Guterzuglok.
