By default, OpenTTD and many similar games have a competition mode, where the goal is to run competing players (either AI or human) out of business a la Monopol

By default, OpenTTD and many similar games have a competition mode, where the goal is to run competing players (either AI or human) out of business a la Monopoly. In practice, it's a sim game at it's core, so the process of building a functional transportation system is a goal in itself.