the video demonstrates: three kinds of colliders (boxes, spheres, and points) anchored to meshes, moving according to keyboard input which is coming from the entity system. the colliders themselves are laid out in blender along with their meshes
a collision component is added to entities for every frame that they are colliding w/another object. this means your collision code lives w/the rest of the ECS code. here's everything that handles the projectiles (aka "zaps"), collision at the bottom