Yes, it's *possible* to push Odd off the level, e.g. by hitting the poor little bot in the head with a giant stone slab! While it's a neat little easter egg, many users reported it as a bug. So now the Game Over dialog will pop up if you fall off, to make it clear you can't climb back up onto the level.

The golden cube is a reference to a famous indie game. Can you guess which one? 🙂