Challenging! It's all Sandbox ATM with a Career path in the future
First, there's making a ship ...
Then there's trying to get a ship into space
Obtaining a stable orbit is the next challenge.
Landing on Mun and Minmus (the two moons) (or even getting close ...) is the next goal
Getting Kerbanauts to those moons would seem easy after that.
Ahhh - a space staion. I could use that as a fueling station ...
... but that means I have to dock ...
And now? Off to Interplanetary Exploration!
There's lots of Tutorials and 'how-to' guides so don't let the Math and Science fool you. Once you learn to safetly dock and create a station then most of the terms and numbers stuff is pretty easy.
My station has progressed! Behold, my creation!