Terrible. Avoid due to junk dpad and compatibilty issues
First of all the DPad is junk. Pressing up on it makes you go up/left or up/right, the same thing with down.
Second of all something is wrong with the way this device is detected by the underlying OS. Often it happens that plugging in two of these makes them inseparable and detected as one.
For a good experience get a real NES controller with an NES- USB adapter.