First of all what is the developer of the game actually developing in the game?

Is he the one who make the renders? Or he is the one who is doing the codding? Or may be he is the one who is doing both! In that case I believe that what is he saying, because codding + rendering is something that requires a lot time. But otherwise if he is doing half of the job I don't believe in a single word of that what he said. I know what is to do renders of animations and pictures and once you got the right settings you are going to set the scenes pretty fast and the PC will do the rest, so I don't see how he can suffer from that. Else if He is doing the codding, that might be actually true, codding is thinking, codding is testing, codding is very difficult, but for a game where your choices are not effecting the story of the game or the end of the game I don't see it so painful. Most likely the problem is way more deeper and He just cant share it with us. Even if He quit the game, which is very unlikely to happen, don't blame him. That's his project, no company owns him. As the Joker said: " if you are good in something... don't do it for free" so yes he is going to work for money.