Object appears flipped in game engine

Hello guys,
I recently started learning BGE, but there’s one issue that baffles me. I made a simple object which when rendered using the Blender Render will look like this:

But when I start the standalone player, why does it appear like this?

Where did I go wrong?

The face normals of your mesh are flipped.

go into editmode - select all faces - <w> flip normals

That solved it. Many thanks!