Hi,
Just to check a few things...
Is it just the mole you're not seeing? Can you see the hole and the dirt okay?
If you double click on the mole object in the hierarchy window, can you see the mole in the scene view?
Does the mole not appear in the Game view at all, or only when you press the play button?
My first thought would be that maybe the mole isn't positioned correctly on the z-axis - remember the higher the z position value the farther it will be from the camera so it could be the case the mole is behind some of the background objects. Alternatively, if the z position value is too small, the object could be behind the camera so won't be picked up by it.
At the end of the Game Objects tutorial page, you can download an example package of what your project should be like at that stage, so you can compare your project with ours to see if there's any differences. Or you can package your project up and send it to support at unikronsoftware.com which will make it easier for us to troubleshoot.