Hello there.

My name is Kevin "Biomech" Putzier, General Manager of the GameCredits (formerly Gamers-coin) project. We have prior claim to the GMC ticker. Given the number of altcoins, I am proceeding from the assumption that you simply didn't know. Please choose a new ticker and inform your exchanges of the same. We are already well established with the GMC ticker, and would like to avoid confusion and conflict regarding this matter.  

Thank you!

EDIT, for more information regarding our coin, please see this thread, and reference the original. We've been around for a while https://bitcointalk.org/index.php?topic=1010745.msg10966191#msg10966191