You need to pack a "UnityPlayer.dll" with your game for people to be able to play it apparently. It doesn't work for me because of this error:
Library UnityPlayer.dll (which is needed by L"Z:\\home\\hazarth\\Downloads\\mini jam 117.exe") not found
A quick google reveals that you should pack the exe, the UnityPlayer.dll and possibly also the "data" folder if you have one.
hope this helps :)