The text in the arena mode appears too slow. The intro is interesting the first two times you see it, after that it lacks an obvious skip intro button.
As for the libraries, I can suggest you Qt4. It is cross-platform, has support for console applications as well, and sound and networking support, which you will need in new versions. It has multiple licenses available too, with one being LGPL, so you can make a closed source application with it if you wish to, as long as you dynamically link the Qt4 library.


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