GameMaker Studio caters to entry-level novices and seasoned game development professionals equally, allowing them to create cross-platform games in record time and at a fraction of the cost of conventional tools! In addition to making game development 80 percent faster than coding for native languages, developers can create fully functional prototypes in just a few hours, and a full game in just a matter of weeks.
Its best for beginners, no one else. Game Maker is very weak unless you use external DLLs, I used to use this before I became a master at C++ and OpenGL, I have to say that Game Maker is very primitive compared to C++ (Not that that isn't to be expected)