In Whistle Mountain, take your company's massive profits from all of that railroading and invest them in new technologies, deep in the Rocky Mountains where there is an abundance of resources.
Your workers build crazy arrays of scaffolds and machines, upgrading your abilities and collecting resources. As you build with the help of your airship fleet, the mountain's melting snow causes the water below to rise higher and higher, putting workers in danger and increasing the tension on the dynamically-changing board. Because the resources you gather are determined by what players build, each game evolves differently, resulting in endless replayability.
You have to choose between acquiring new abilities and enhancements for your airships and workers or building all sorts of contraptions as quickly as possible in order to achieve victory on Whistle Mountain.