Scene Glitch?

I have a 5x5 (tile) scene with an actor near the center. It looks fine in editor mode, as you can see by the picture, but when I go to test game it suddenly in the top left corner? Glitch? Bug? Or am I doing something wrong?

It might be because of the scene size is different than the game size, that's my best guess.
What's the game size and scene size?   

Oh thanks! I didn't realise screen size mattered too Thanks for your help!

No problem.