Sid Meier's Railroads! is a game that first came out on the Windows platform in 2006, according to Wikipedia anyway, and I remember buying a copy and setting up Parallels and Windows on my Mac at the time just so I could play it. It's now available on the Mac App Store for $29.99.
I've always loved the tycoon style of game - i.e. SimCity, Transport Tycoon, etc. - and Railraods!1 is a great game in that style.
The game is heavily focused on economics – players have to build and sustain entire industries using the railroads they develop. Gameplay changes from previous editions of Railroad Tycoon include a system where new technology is first auctioned to the highest bidder. This gives the player a ten-year exclusive use of that technology. Similarly, individual industries are also put up for auction amongst players. Tracklaying is automated and much easier than other editions of Railroad Tycoon. When combined with the more "compressed" terrain, it allows for tactical placement of track to obstruct and frustrate opponents.
Part of the fun is just laying tracks and seeing your little trains run on them like a personal train set that you could never afford. But there's also a whole lot of strategy and economics at play that keep it interesting beyond just making trains crash into each other.
The game also allows head-to-head play over a LAN or the Internet, supporting up to four players per game, either human or artificial intelligence.
Who wants to set up a LAN and have a Friday night of Railroads!?2
Sid Meier's Railroads! Screenshots permalink
[gallery link="file" columns="5"]