Tom - not sure if it's better or not, but Gideros Studio may answer your needs. It's a cross-platform mobile development environment with physics, in-app purchase, Gamecenter, Storekit, hardware, as well as tweening, particle engine, and many 3rd party IDEs like physics editor, sprite helper and level editors.
It also supports native code (plugins), meaning if you have a library in C, C++, Objective C or Java, you ca integrate it next to Lua, the programming language Gideros Studio is based on. Moroever Gideros Studio IDE uses over-the-air (Wi-Fi) testing, so it's possible to test the application instantly on a real hardware.
It uses Box2D as a backend for physics.