Wouldn't be so forgiving in a real game... but it's neat. If you avoid big mistakes(too long & narrow routes, Routes with tech stops, too many fleet groups, bad pricing, too small planes on long routes, too big planes on short routes, bad fleet choices, unadequate pricing, planes under-use, flying popular(therefore expensive) brand new leased planes on low-yield routes(not enough demand, or too much competition), too low pricing, and did I mention bad pricing or launching a price war against a strong opponent?), you should survive a real game.
Note that I'm deliberately guilty of 3 & half of those mistakes, but now I've got enough experience to know when to fly long, narrow routes with small birds. Don't try it unless you've got plenty of margin. And the 1/2 mistake was forced by a tricky choice of second airport(London City is plenty of fun & opportunities, but the plane list is, errrrm, limitative, to say the least. Ejets are so in demand that their cost is insane in current GW3, while nearly as good J928 are half the price. And I couldn't go for them).
But it's soooooo funny to make SW3 fly between Edimburgh & Kangerlussuaq, or Nice & Bobo Dioulasso(don't expect any profit on those lines, ever, simply because of the tech stop, though, they are just for the fun. Noone else flies there, and I'm leader in served airports by 68 units. It's worth the few tenths of a percent margin loss).
And Never, ever, forget to adjust your prices. It's probably the mistake that kills the most companies. I make a lot of stupid things, but cannot afford this one. In beginner's world, who cares? But in competitive, long games, with fuel prices at 1350$ per ton and good planes having their prices doubled because of insane demand, you'd better milk your customer base as much as you can. Some players with huge companies do not micromanage prices as much as I do, but they very regularly adjust overall prices. They'd be overwhelmed without it. And if a player launches a price war against you, bite the bullet, but don't go too far down. Let him die out of underpricing.