If in a game, there's a particular idea that's not a defining part of the game, but strikes you as being great and under-exploited, is taking inspiration from this idea allowed ?
Neolander added on
(As for Mary Sue, I have yet to fully understand that concept :) It seems to me that this name designates a character that the writer is extremely fond of and/or has put a lot of himself in, but I've yet to be sure)