riddle - I'm purple and small, what am I?

I'm purple and small,
not hard to make at all.
I take you to new places,
Where you will see some new faces.

I'm part of the world, yet take you away,
When you step through me, you see mostly grey.
You must walk through me to complete the game,
And when you see me, you'll know my name.

Sorry for the lame poetry, but

HINT (big hint, so use only as a last resort):

I am related to https://www.youtube.com/watch?v=gMoS2FvkyLE

Answer

Sounds like you are a...

Minecraft Nether Portal

I'm purple and small,
not hard to make at all.

Made up of only an obsidian frame, then lit on fire.

I take you to new places,
Where you will see some new faces.

A portal ... well, takes you somewhere else. This one in particular opens up a new dimension.

I'm part of the world, yet take you away,
When you step through me, you see mostly grey.

Stepping through, your view is obscured by a purplish hue, and you will be whisked away from the Overworld.

You must walk through me to complete the game,
And when you see me, you'll know my name.

A portal is pretty clearly identified. You must complete tasks and gather materials in the Nether to reach The End.