Given the name, McCoy is probably a main character. There may be other characters that play important roles too. For example, there could be a mentor figure who helps McCoy in the game, or an antagonist who tries to stop him from achieving his goals in the game. Without reading the story, it's difficult to name all the main characters, but McCoy is definitely a key one.
Since the story is called 'the mccoy game story', McCoy is most likely the central character. However, there could be other significant characters as well. There might be a sidekick who accompanies McCoy on his adventures in the game. There could also be a game master - like character who controls the flow and rules of the game in the story. And perhaps there are some rival players who are in direct competition with McCoy, all of which could be main characters depending on how the story unfolds.
I don't know for sure, but McCoy is likely to be one of the main characters since the story is named after him. There could be other characters like his friends or opponents in the game.