Games that actually reward you for the time you invest in them

I know that lately there are two types of opinions:those who complain that games are too hard, and those who complain that modern games are too easy. As for me, I’m somewhere in the middle,I like a challenge, but a fair one, and I like to invest my time into games that will reward me for it. These games, in my opinion, are a perfect example of games that reward you when you invest time in them and make an effort to get better; the overall experience becomes twice as good because of it. Are there any games that have triggered a similar reaction for you?