itch.io

When the phase 3 image appears you need to press the green flag, then you can play phase 3. Phase 3 was canceled along with the update, that's why not all the animations are done 

Unlock phase 1, and switch rapidly between phase 1 and phase 2. This will then bring you to phase 3

To access the phase 3, you need to swap between phase 1 and 2 for a bit

Actually, I did find it >:) 

You just need to swap from phase 1 to phase 2 and vice versa for a bit