Hate to break it to ya, but any free FPS makers are generaly awful. I've tried to look for some good ones but usualy they're all less flexible then just using C++ or another language. If you want to make a good FPS I'd suggest learning C++ but if you'd like to look at some slightly less fluid FPS creation check out his link. (Typically free FPS creators all use the same HUD, weapons, character creation etc)