The phrase "multiplayer aspect" refers to a feature or part of a game or activity that allows multiple people to play or participate together at the same time. Full definition
The online multiplayer aspect of GTA IV seemed like more of an after - thought (in my opinion anyways) but I have high hopes for the online experience this time around. (thatvideogameblog.com)
This also translates into the online multiplayer aspect of the games. (reviews2go.com)
There is almost solely a local multiplayer aspect to these games, often between 2 - 4 players. (mattsgameexchange.com)