The typical round in OpenTTD takes place during a time period that goes from 1950 to 2050, a time in which your objective is to get the highest score possible. You can do this by having a good and constant source of income, a large fleet of vehicles, and a hefty number of goods delivered to their respective destinations.
In the beginning, you can create roads and trucks, establishing basic comercial routes that aren't very profitable. As you advance in the game, you'll be able to start setting up commercial routes by air and sea that will give you higher profits.
OpenTTD is one of the most famous free management games that exists thanks to the fact that it's constantly being updated. In the beginning, like what happens with almost all games in the genre, it can be tricky to get the hang of the interface. But as you play, you'll get used to it and can start exploring all the possibilities this excellent strategy title has to offer on Mac.