A few years ago I tried to get into Unreal, but after a while it's easy to come to the conclusion why most game studios aren't one-man companies. Unless you'd just asset flip, or go for a pretty basic kind of game, it's just so much work that it stops being a fun hobby and just becomes something that would turn into a full-time job, without pay lol.
Used to do modding and maps for various games back in the days, like Battlefield 1942 and Jedi Knight games, even dabbled some in 3DS Max and Cinema4D, was pretty fun creating stuff. But taking on an entire game concept is so incredibly daunting.