Simulators are often dumbed down, or complex to the point of absurdity.
KSP has a steep learning curve, but an easy interface.

I stayed up all night until my rocket could make it to orbit.
Lost many hours of sleep my first week of playing, getting to the moon.
Lost even more sleep, getting to the moon and back.
Lost more still docking for the first time.

And I don't want any of that lost sleep back, this game is WIN.

Simulators are often dumbed down, or complex to the point of absurdity. KSP has a steep learning curve, but an easy interface. I stayed up all night until my rocket could make it to orbit. Lost many hours of sleep my first week of playing, getting to the moon. Lost even more sleep, getting to the moon and back. Lost more still docking for the first time. And I don't want any of that lost sleep back, this game is WIN.