No
no
No
no not yet...
yes
your kidding right...
In maplestory, portal was created because they wanted player to travel from place to place
In order to play the mod Portal: Prelude, you do need to have Portal.
In the game Portal, yes.In real life... there could be something called a portal gun. But there's no known way of making something that works even approximately like the gun in Portal.
In the real world sadly that's impossible. In the show, there's the movie "Equestria Girls" of which Twilight travels (by portal) to another world where they are human, and there is a portal that stays open for 3 moons, back to Equestria. So in that way, yes there is that portal.
Okay.. what? You can't make a portal to cartoons because it isn't a place.
No. Such a thing is not possible in real life. Even if wormholes exist, they would not work the way they do in the game.