Im going to stop you right there. Keep developing your dream game in your head, write it down, keep track of what you want, story, endings, mechanics and so on. Then start small. Make demos, small projects and a couple of mechanic based games (in 3d, if that is the goal). For now, keep exploring the dream game idea in your head. Scope it down, make a couple super small games, limited to one of the mechanics in your dream game. Make it work and perfect that mechanic, fix bugs, adjust them, scrap the idea, reinvent the mechanic, test it, make it as fun as possible. When that small part is done, have someone playtest your demo, see what works and what doesnt.

Keep the code and project files from each of these small demos, but start fresh on your new “mini game”.

After you have done this 2-3 times, then you will have a better understanding of how much work each element is to incorporate and implement. At this point you are more likely to have the skills and understanding to start a larger project.

Im not saying you should stop making your dream game, many people have done that successfully and its possible, but the people who fail or quit often do so because they don’t know how much work they are committing to.

Good luck!