It's a great SDK for making cross-platform 2d games. (For cross-platform 3d games, Unity is currently the most popular choice.) You are sacrificing control of the technology by using it, or similar products, but that's only relevant if the underlying technology is more important to you than the game itself.

If the technology is important, you're probably better of creating your own engine (this will take a long time), or licensing an existing engine (i.e., the Unreal Engine) and modding it as necessary.