In the early days of gaming, not much thought was given to what was or wasn't a game. Some games required a special controller while others revolved around text commands, but it didn't matter how they were played. People just enjoyed them.
These days, things aren't so simple. Gaming is bigger than ever, and the gaming world has gotten a lot more complicated. Games are categorized as "casual" or "hardcore", as are the people who play them. Titles like The Fullbright Company's Gone Home are lauded as game of the year by some, while others don't see them as games at all.