Recently while working on teaching myself to work with libgdx, a cross-platform java game development kit, I discovered that someone used it to create a port of Flixel, my favorite ActionScript game engine. The port is called Flixel-GDX. This was great for me because I had worked with Flixel in the past and I loved the simplicity of the development process with it, but I wanted a Java solution that I could use for mobile games which is why I switched to libgdx to begin with. In my humble opinion this is one of the best game development libraries available, especially for beginners. libgdx is very powerful and built for fast cross-platform development, it also allows you to write your code once and build it as a Desktop, Android, iOS, and html5 application, but it has a steep learning curve for beginners. Flixel is super-simple to get the hang of once you build a few small projects, but it’s strictly for flash games. Flixel-GDX is the perfect marriage of the two, offering the simplicity of Flixel built on top of the power of libgdx.
When I started playing with Flixel-GDX I ported a prototype space shooter that I wrote with Flixel as a proof of concept project. (I will post it here eventually) Originally, the whole project was just an excuse for me to play with a parallax scrolling star field as a background for the game. Once I ported it, I was inspired to create an entire prototype game. I decided that the player would tilt the phone to move the ship side to side and touch the screen to fire. I set up my project and it actually ported very easily from the native Flixel project. In less than 30 minutes I was up and running. Over the next few weeks, in my free time, I worked on the game here and there and now my prototype is almost where I want it to be. The documentation is great and the Flixel code has been ported so nicely that even following suggestions intended for ActionScript on the forums is simple.
I recommend checking it out!