Imagine being Mario... standing in front if a pipe that blocks your view. It must be terrifying to know that any millisecond a bullet/wrench might phase through the pipe and kill you.

I kinda wonder about 3D video game characters. Are they actually 3D or are they 2D? Would they be the bits inside the computer (and thus the complete idea of the character), or the pixels on the screen (a 2D representation of the character)? If they had sentience, would they possibly be three dimensional beings trapped inside a two dimensional world?

If you like Flatland and video games, you should try some Paper Mario games.

Flatlanders can only see other flatlanders in a single dimension: a line. All flatlanders would look similar, no matter what shape they were, however from different angles the line that represents them would change length with some shapes and not others. A sphere is one of the shapes where the line would stay at a constant length.