In contrast to Air Bucks, Airlines is a complex sim with a steep learning curve. Although the game offers a lot of real-world options and a wide variety of airplanes, the designer somehow chose to make the game play in real time. Thats rightbusiness acumen is not enough to succeed in Airlines: you need to think and act quickly before a day is over (or use slowdown programs to make it run very slowly). The clock advances 4 hours at a time, and there never seems to be enough time to do everything in a day.Once you get used to the real-time gameplay, though, Airlines will draw you in (that is, if you like serious business sims) with its solid economic model, tough computer competitors, and a range of options that allow you to fine-tune your airline in much greater detail than Air Bucks. I found that the supply and demand curves in the game are a bit too inelastic and loan sharks a bit too unforgiving, but these are just minor gripes that make the game more challenging.