I have two very different kinds of games I did this with.
The first was Undertale, didn’t really get into it at first and stopped playing it around half way through. However after I watched someone else beat the game I got a lot more into it and finally beat all the main endings. Really liked the story and it quickly became one of my favorites after that.
The other is the Crusader Kings games. I got one of them when I was pretty young through a humble bundle and did not understand how it worked at all. Then near the end of highschool I finally tried them again along with playing Stellaris and thats when I was finally able to figure out how to play them and got super into a lot of Paradox’s games.