I think you are trying to ask how to playback the animation that you made with IPO’s? If so, you need to add an always sensor, add and controller, then an IPO actuator. Set the frame range to be played back and what looping options.
I hope that is what you were asking about. Also, you dont have to use an always sensor, it can be anything. As for the end of your animation and having it go back to the beginning. Blender can do this for you with the loop option.
Since your IPO is set up that way you might notice a hitch when played back in the game engine if you use the looping option in the actuator. Due to the fact that the first and last frame are the same, that motion or position will appear twice in succession possibly resulting in a stutter.
Hope that helps, if not, maybe post a blend at some point and we can fix it.