Pokemon Stadium 2 is alright, except it gets very very very gay when the ground becomes a treadmill that pushes you off and you cant get back on. Especially if you have a character like Ike who is terrible at getting back up on stage.
Hyrule Castle? There is none, I believe you are referring to Temple. Its an alright map..better than Rumble Falls, or Rainbow Cruise, or Pokemon Stadium 2 . Atleast theres nothing that pushes you off the screen.
I know I hate the sample stages too! Like the maze is just retarded the only way to get a kill is to get them on the top of the stage, and when your trying to get a smash ball, theres too many walls and the smash balls can go through the walls so its a big pain in the neck.
New Pork City is alright. Its not bad at all. No obstacles or anything.
Except the Pink Monster that causes 200% damage then sends you flying, but its very very easy to avoid that. It can be used very usefully with CPUs because they will walk right into him.