one example would be a better portal gun, that can now throw portals onto more types of surfaces.
I remember how satisfying it is in games like prince of persia to get an upgraded sword that now has the ability to cut right through walls.
so it makes sense to me to have a portal gun that has more features...
portals onto more surfaces... makes portals of differing sizes... gee if you make a small portal and a large one, do you come out the same size? or is that a way to get bigger and smaller? heh that would be hot if you could grow super big or tiny tiny... although it could be rather scary if you go into an infinite ceiling floor loop and keep shrinking for a few hours. hm. ok maybe not haha.
but to have an enhanced gun that shoots more than just two portals, or can shoot more than one set of two perhaps (ya that's better--more than one set of two) as well as a gun that can shoot portals onto new surfaces, and moving surfaces... ya. mm.
and the cake. they can make better cake.
