If you could upload the blend, I'm sure someone might spot the answer right away.
All I can think is maybe the animation is at x,y,z location and your camera, even though it is set to look at the animation in the editor, is actually looking at a,b,c location in-game.
Make sure your animations are starting at home (0,0,0) and not offset somewhere else. After you confirm the animation, then you can move it somewhere else.
It also occurs to me maybe you have it on a hidden layer. Check the camera and object layers are visible and try again.
OOORRR the object render option is deselected from the outliner view / object's physics tab. Check that as well.