Use your teleporter, go into Galaxy Island. I recommend drinking a smoothie for faster speed and higher jumps for a later part of this. I also put lights on the door that will let me know which door "takes me home" out of the island once I come back from down below in the caves.

• Immediately make a right into the little area past the bridge and enter.
  
  
• Walk in, drop down & make your way through the cave and go through the middle door with candles.
  
  
• Once inside follow the path up the stairs and proceed to jump until you get across the broken bridge and up through the higher pathway to the door. Enter through the door with cheesecakes off to the right.
  
  
  

• After entering the cheesecake door make a left into the 3rd door with the goat plushie in front of it. Walk further down the stairs into the door down below (bottom left).
  DO NOT jump up top right like I did and go into the door above, it will take you back to the main door entrance where you first saw Max talking to you about his hat missing etc.
  

• Start making your way down the stairs following the wall along the left. Once you walk through white pillars to your direct right there will be pink candles and an area that you will have to climb up.
  The candles on the floor are a good marker for whether you've gone too far or not far enough.
  
  
• JUMP JUMP JUMP.
  If you drank a smoothie you will have extra speed and higher jumps to make this easier.
  Be careful, it's easy to fall a lot and you'll have to go back around but the walk isn't too far if you do fall.
  Once you make your way up, on the white plaque there will be a MUSEUM KEY waiting for you to pick up.
  
  
• Grab it and drop down and make your way through the door at the bottom of the cave that you will be able to unlock with this key you just obtained. Walk through the unlocked door and walk through the purple one inside to the right.
  

• After walking through the door, Vorlen will be standing right here.
  
  
• Talk to him, he'll let you know he really likes the Milky Way painting and that he pretty much wants to take it back to the village. Go around back and grab the painting on this wall:
  
  To the right of this wall will be Rhubarb Jam. I grabbed it on my run just to unlock it since I still haven't unlocked Rhubarb seeds and I don't know when I will get them so hopefully that will trigger something later in the story. Maybe maybe not but I grabbed it just in case.
  (I ended up getting it from a lucky box and reaping it for seeds later)
  
  
• Talk to Vorlen again who will be happy about the painting and will let you know he will return home soon.
  If you have the weed killer in your inventory, this will be a time you can spray it on him to complete the Mushroom Panic quest from his daughter.
  
  
• Exit through the pink door upstairs. It will take you back to the main door that would meet Max at when he was in Galaxy Island. TURN STRAIGHT AROUND go out the purple door behind you.
  
  
• Make your way back up the cave through the tunnel, climb up the stairs and go through the purple door and you'll be back at the top of Galaxy Island. You can make a left once you come out the little cubby hole, cross the bridge and that door is your exit off the island.
  

I realized that I probably missed the 4th door from the very beginning because like I said I went top right instead of bottom left which took me back to the main door. Also around that time I ran into Tomti and went through the gaming room so I never remembered to go back to that section and explore again just in case I missed something.
What a huge thing to miss btw.
All in all, once you return back to the village you can complete the Mushroom Panic quest if you haven't already and if he's not already back home, Vorlen will be back by the next day like normal.

It bothered me a lot that this was something that could be missed so easily if you were focused on Tomti's riddles so I wanted to create a walk-through for anyone who was as stuck as I was.

Now if only someone could help me understand why some bugs aren't spawning in Galaxy Island and the Island Portals I'd greatly appreciate it. (I mean it, please help)
Other than that, this is everything for the guide for missing Vorlen.