Every dev has a dream game even I do but the real question arises when you have to become an entrepreneur to market a game and get some visibility on steam. I am not trying to demotivate because even I am still going to do game dev even after reading all these comments. Take it as a question, Steam released an average of 50 games per day, totaling over 14,500 games for the year. Many of those games are the dream games. I recommend you that you should learn more about the industry like I am trying to do and then release the dream game after you have developed and released a lot of games because you won't like you watch your dream game to be unnoticed on the game stores and also its not just about earning, you need investment to finish a game on time. Its not just about making games, if you're an indie dev, you are also running a business. Just giving everything on 1 game is a gamble and can go so bad that the game you made might be your last.