The dream was something vaguely kingdom hearts-ish, but I can't remember exactly how now. I was going to different worlds, and you could get to them from a hub area that was basically an amusement park. Normally you'd have to unlock the different worlds, but I had "played" before and knew shortcuts. Certain early areas were connected to later areas. There were spots that had portals that would open if you said the right password.
I walked up to one of them, located in a normal house, in its living room I think. It was a mirror, but it opened like a window. I prepared myself and said the password, "cat". Immediately the portal pulled me in. I wasn't standing in quite the right spot, or the mirrorwindow wasn't open enough, so I bumped my head on it. But that didn't matter, as the world around me started to fade away. All the features blurred until I was in a dark grey void, like the sky before the sun rises. Gravity had changed, and my standing position now had me floating with my back facing down. I was there for just a moment, and then I started to fall.
The fall lasted for maybe 1 or 2 seconds. I felt the acceleration and the wind rushing past me, and then I landed on something soft. I had successfully teleported. There was something about the fall that felt real. So real that I thought to myself "this can't be a dream, because falling in a dream doesn't feel like that". How silly of me.