Activating Missions in Custom Sonic World stages is Pretty simple, Just follow the steps below and you'll be good to go .

Adding Missions to your stage Edit

1 - Create a .txt file and Name it "Missions" .

2 - Copy and Past the following contents to your "Missions" .txt :

<mission1 is="0" time="440" idealtime="410"/>
<mission2 is="10" time="300" idealtime="260"/>
<mission3 is="11" time="375" idealtime="315"/>
<mission4 is="12" time="150" idealtime="130"/>
<mission5 is="7" time="300" idealtime="260"/>
<general idealscore="15640">
3 - Set Mission type for each Mission number .

4 - Set the Minimum score points required to get "S" Rank in the "general idealscore" line .

5 - Save your .txt as an .xml without changing it's name .

6 - Move it to "media" folder .