Complete solution with answer and video walkthrough
They reached to the 2nd gate. They must solve its puzzle
Drag the yellow orbs to light up all 4 orbs in the middle. You can put a 4th yellow orb on the gate. Drag the ball next to the rock to add the 4th orb..


They must find a way to get across

The Slime King confronts them

End the war between the red and blue slimes

The Slime King told them to go through 2 doors towards the East

Alyx must fill the bottle with the Fountain of Life's water

The cave is collapsing upon them! Find an exit

They are close to the surface, but they must find a way to dig out

Dracula stole the water! Stop him