You'll need to connect a
body_entered signal from the Area2D to the KinematicBody2D.
You can do that by accessing the "Node" tab when the Area2D is selected
From there, you right click the
body_entered signal and then "Connect"
After that, a dialogue box will appear, wherein you can select the SpaceShip node
Clicking "Connect" button on the bottom will create a new function, in this new function you can do whatever you need pertaining to the victory state.