Pre-Odyssey Mini-Game

You can find the file for this in "element\interfaces.pck.files\interfaces" and would need to look for the file "winmain2.xml" The mini-game was long since removed with the update for Odyssey but all the components are still in-game. You just need to add a new button for the mini bar (example on the bottom of it pre-added). Pre-Edited Mini-Game (Feel Free to Use): 
 <DIALOG Name="Win_Main2" Width="367" Height="48">

   <EDIT Name="Img_Back" x="18" y="23" Width="346" Height="25" ReadOnly="true" MaxLen="20">

       <Text FontName="方正细黑一简体" FontSize="10" Shadow="255"/>

       <Resource>

           <FrameImage FileName="frame\sback.tga"/>

       </Resource>

   </EDIT>

   <STILLIMAGEBUTTON Name="Btn_Produce" x="64" Width="36" Height="48" Command="wproduce">

       <Hint String="Crafting (^00ff00 O  ^ffffff)"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="Button\SProduce.tga" FrameMode="1"/>

           <FrameDownImage FileName="Button\SProduceDown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>

   <STILLIMAGEBUTTON Name="Btn_Action" x="280" Width="36" Height="48" Command="waction">

       <Hint String="Actions (^00ff00 U  ^ffffff)"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="Button\SAction.tga" FrameMode="1"/>

           <FrameDownImage FileName="Button\SActionDown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>

   <STILLIMAGEBUTTON Name="Btn_Friend" x="100" Width="36" Height="48" Command="wsociety">

       <Hint String="Friends^ffffff (^00ff00 F ^ffffff)"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="button\friend.tga" FrameMode="1"/>

           <FrameDownImage FileName="button\frienddown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>

   <STILLIMAGEBUTTON Name="Btn_change" x="28" Width="36" Height="48" Command="wchange">

       <Hint String="Transform (^00ff00 N ^ffffff)"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="button\stransform.tga" FrameMode="1"/>

           <FrameDownImage FileName="button\stransformdown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>

   <STILLIMAGEBUTTON Name="Btn_Rank" x="208" Width="36" Height="48" Command="wranklist">

       <Hint String="Player Rankings (^00ff00 I  ^ffffff)"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="Button\SRank.tga" FrameMode="1"/>

           <FrameDownImage FileName="Button\SRankDown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>

   <STILLIMAGEBUTTON Name="Btn_Achievement" x="244" Width="36" Height="48" Command="wachievement">

       <Hint String="Achievements (^00ff00 V  ^ffffff)"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="button\Achievement.tga" FrameMode="1"/>

           <FrameDownImage FileName="button\Achievementdown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>

   <STILLIMAGEBUTTON Name="Btn_Faction" x="172" Width="36" Height="48" Command="wfaction">

       <Hint String="Alliance and Clans (^00ff00 G ^ffffff)"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="Button\SGuild.tga" FrameMode="1"/>

           <FrameDownImage FileName="Button\SGuildDown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>

   <STILLIMAGEBUTTON Name="Btn_Team" x="136" Width="36" Height="48" Command="wteam">

       <Hint String="Party Settings (^00ff00 T  ^ffffff)"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="Button\STeam.tga" FrameMode="1"/>

           <FrameDownImage FileName="Button\STeamDown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>

     <STILLIMAGEBUTTON Name="Btn_game" x="319" Width="36" Height="48" Command="wgame">

       <Hint String="ESO-MiniGame"/>

       <Text FontName="方正细黑一简体" FontSize="12"/>

       <Resource>

           <FrameUpImage FileName="Button\sgame.tga" FrameMode="1"/>

           <FrameDownImage FileName="Button\sgamedown.tga" FrameMode="1"/>

       </Resource>

   </STILLIMAGEBUTTON>
</DIALOG>