When we first approach to making a game we think "doing a game will be a huge project!!". If making a Site sometimes all the UX studies we made, where to put the content, what is more relevant and so on take time and work, making a game is that elevated by two hundred times!!
In a game you have the Story, the Game Document, Game Art, Ui Design, User Experience, Sound and the coding and this is not as simple and in a small scale like a webpage.
Besides this, the most part of the time it's all done by one person, like my case.