I enjoy the game because of the learning curve. When I first got the game I couldn't get a rocket into orbit. I just strapped a Kerbal onto a makeshift rocket and saw how far I could get him into the air. Slowly, I started getting things into orbit. I then starting gettings thing back to the surface from orbit. I then managed to get a rocket to do a free-return around the Mun. Eventually, I successfully got a Mun landing AND got them back to Kerbin. I've been having a blast working through career mode collecting science. I'm not efficient at it, as I try to create somewhat plausable rockets (no ungodly wide rocket designs). My current masterpiece is a rocket with a small lander than can get a Kerbal to the Mun and Minmus and back. I've also gotten the same design to do an orbit of Duna and Eve with enough fuel to return safely. My first ever orbit of Duna, I royally screwed up the return window. I waited in orbit for the planets to align for a proper return window. I set up the return burn and realized I was orbiting Duna the wrong direction. Rather than try to fudge the return burn on the opposite side of Duna, I thought I'd get cute and transfer to Duna's moon THEN do the return burn at the proper angle. I screwed up the time acceleration and ended up slingshotting myself out of Duna's encounter before doing the proper return burn. Orbiting the with little fuel reserve, I waited until I hit my apoapsis and lowered my periapsis to just below Kerbin's orbit. In a stroke of luck, I wasn't too far away from a Kerbin encounter on the first pass. I fudged my trajectory a number of times until I was able to get a Kerbin flyby at 42k. Using the aerobrake and the last of my fuel, I was just able to enter an orbit around Kerbin as my fuel ran out. From there, it was just letting the repeated aerobrakes bring Jebediah home a little more than a year after he left. Right now, I'm trying to build a lander that can redock with the rocket to allow a Duna moon landing. The increase in weight has rendered my previous rocket design obsolete, so now I'm trying to either build a heavy lifter, or try to find out how to build a spacestation that I can lift the rocket and lander to so I can launch fully fueled from there. I'm a long way from not even getting out of the atmosphere. The game sort of reminds me of when I'd play with legos as a kid. Just take a bunch of random parts and see if you can make something cool with it. In this case, the something cool is an interplanetary rocket.
