Game Maker is a game engine centered especially on 2d games. It is very active, constantly coming with updates and the games can be exported for practically any platform, including mobiles and web(html5).
It has a physics library(box2d) and it has its own script. The script is not a well established one so if you want to develop games in Game Maker you have to learn that script. The good part is that when developing a game, most of the thing you do are code-less, but from time to time code is necessary and only o bit has to be written.
