If you have a real floppy drive in your PC then just copy the extracted file to the disk. Inthe emulator disk menu can mount the real disk with pressing the A: button (you got a image file name: \\.\A: ).
And at the IS-BASIC prompt type: load "game.com"
Most of programs starting with the .COM file. If the program have a file named a START, then more easy, just press F1 key, this automaticaly load the START file.

If you not have a floppy drive, then use a FILEIO mode of the ep128emu. In the configuration menu load any configuration with FILEIO. EP_128k_Tape_FileIO_TASMON.cfg is recommended (fast memory test is also included)
With the Set working directroy select the directory where you store the extracted game files.
Then you can use the load "game.com" commad, the emulator is load from your specified directory.
Pressing F1 key (START command) is also can be used, then a file selection window will be displayed, and you can select which (.COM) will be loaded.