You are right.
Art is about 50%, design is bout 30%, ingenuity is 10%, direction is about 5% and programming is another 5%
Art and sound are by far the hardest thing to get, and even harder is to get good art direction, by this i mean and entire cohering concept that work form began to end.
This is why big companies can make better games, it is not because they are better people it is because they have more money. So they can to make few mistakes.
If art is bad the first time around, they just lose some money and start over. It is the sad reality of what the video game business in going. Big money, the consoles market, and the movies are ruin it.
and only and elite people can get into it.