Who exactly is Nardo Polo?

Mark was probably most notably known as GarageGames' internal "expert Marble Blast" player. They referred to him as the World's Greatest Marble Blast Player (in fact, in MBO (you could have special flair text), his handle was Nardo Polo with the slogan "World's Greatest Marble Blast Player"). He is responsible for most of the Gold Times in Marble Blast Gold.

He made a few appearances during the Marble Blast Online era to entertain some of the top players at the time. The highlight was the day he played a few rounds with IsraeliRD, I remember there was a lot of tension in the community at the time as we were unsure if Matan would actually be able to beat him in a multiplayer setting. I think they were on an even skill level but Matan ended up winning a majority of the rounds they played.

~Aayrl

There is a good achievement to answer this:

"Who are you?
I am the unknown. I am the reason you play Marble Blast. I am the reason you cannot reach 3000 Multiplayer rating. I am your worst marble nightmare. I am the one. I am Nardo Polo."