You can select Open from the File menu to open a file. As you can see from this Open window, you can open only two file formats (emm and emx)

Once you have selected a file and hit the Open button, you will see the file properties. When you click OK, the file will start playing.
If the screen resolution of the file is bigger than your screen resolution, it will automatically resize to fit to your window. You can also change the size of the video by selecting “Fit to Window” or “Full size” from the View menu. If you want to watch the video at its original size, you have to unselect “Fit to Window” option. If the original video is bigger than your resolution, you can scroll the video while watching from the Player.