Free Step Dodge

Infinte walls?

Also known as invisible walls. They occur if you juggle someone after you slammed them into a breakable object. At the very end of Zack Island in the sea, there is an invisible wall too.

There are wayy more than that though and i feel they were intended to be a big part of the game.

The least known ones are probably the chains in the lower part of Fuel, the walls were the penguins stand in The Ends of the Earth and the stairs in the upper part of Lorelei.

I would say the same about stages with slippery zones. Slip stun combos can get you a lot of damage and there's plenty of stages with water/ice surfaces.

That's true as well, but they're a lot easier to spot lol.