In my experience, it was easy... until I got to the part of my game that makes it unique. Then it went from easy to very very hard.
That's the thing about engines. They'll get you up and running quickly for basic stuff, but you'll be tearing out your hair when you need to do anything non-basic.
That's the thing about engines. They'll get you up and running quickly for basic stuff, but you'll be tearing out your hair when you need to do anything non-basic.