|Date||Jan. 23rd 2006|
Hobby is the 53rd xkcd comic.
The game refers to the scoring system in several (recent) video games, which not only requires the player to achieve a certain objective, but additionaly deducts score points for mistakes, such as the killing of innocent people.
"The only one of these games I really played was Area 51"
There are two videogames called Area 51. Most likely, this refers to the one from 2005, a first person shooter and survival horror game for Playstation 2, Xbox and Windows. In this game, the player controls Ethan Cole, an operative sent to the infamous Area 51 base to assist in the cleanup of a mutagenic virus.
It is unclear wether "one of these games" refers to video games or first person shooter games in general, or more specificly the kind of game where the scoring system deducts points for errors made.