Depends on your experience. It's probably the fastest pipeline possible for game development of any kind given the power that program has. While in Game Maker you can slap together a space shooter in five minutes because the interface lets you, Unity has a much more balanced approach that is ultimately far more flexible. You can still produce good games very quickly. This is why I encourage learning it, as well as Java which it uses. I wouldn't bother with Python, it's doing its own thing. The language is completely different from C and Java. Python is an interpreted language, so it generally runs much slower than compiled languages like C++, and there's only a couple worthwhile engines out there for Python programmers, like Blender and Panda3D. Languages like C++ and Java are more powerful, much faster, much more capable, and naturally used the most in game development anywhere. You're better off learning one of those, or more than one if possible.