I have always been inspired by the dream of space travel. I became an engineer partially because I want to design interstellar spacecraft. But since the job market in manned spaceflight fluctuates with every election, I will content myself (for now) with KSP. In KSP, you may have over a thousand in-game hours of play, but you can still crash just as easily on the Mun as you did on day 1. You aren't artificially better just because you've grinded out science, or launched over 100 rockets. Your skills (and luck) are earned the hard way. Every mission, I find myself having to solve unexpected problems and having new adventures due to mistakes in ship design or piloting. (Ever try docking without RCS, or delivering a landing stage (designed to be manned) to a multi-part spacecraft without probe cores or kerbals on the key stage). No two flights are quite the same, and every new 'routine' mission has the potential to become another Apollo 13. What other game allows you to feel that kind of accomplishment, and lets you learn so much from failure? It seems like modern gaming companies don't always recognize that people like limits, not in the form of artificial walls or 'levels' to the game's world, but real consequences for player's decisions. Nothing stops me from making a nonsensical rocket in the editor, but then nothing forces the design to work either. That's my kind of game. I play other games from time to time, but I'm always drawn back to KSP--because I feel like I learn something every time I play, and there's always more to do.