This game is incredible and I'm having so much fun!
One thing though - after I defeat the creator, speak to the 'school friend' metal guy and fly upwards towards the planet to fight Mrs Slithers, the portal is not there.
After searching around, I sat on top of the rotating planet and shot my pineapple gun in fury . Suddenly I hear Mrs Slithers talk and say "I only wanted to teach you the true meaning of juice", and I had all these rainbow blobs hit me.
Have I actually managed to kill her by shooting through the planet?
I see from other walkthroughs you can access the doorway here, but no such luck for me. 
Adds to the trippy nature of the game and I could play over an over - but I'm wondering if this is a bug and how to get past it?
Has this happened to anyone else? 

Cheers,

Looking forward to more games from Fishlicka!!