If you want a bit of a challenge, make a clone of super crate box. Or if you want do what I did and make a horror game. Also you said you don’t think you can make a minesweeper clone, that’s fine. Programming is one of those things where you learn along the way, it will be a fustrating learning curve as you will not understand alot of code that you will come accross. But if you really wanted to push your self and make a minesweeper clone, you could either watch a tutorial on it, or download the source code and debug then understand it which is also effective.
But I think you are headed in the right direction, just keep making mini projects. One thing you will realize in coding, when you experiment you will learn new stuff then will be able to use it future projects.
Since you seem to be fairly new, I could give you a step by step guide if you are interested to get you started. (I know it seems contradictory what I said above I am referring to “making mini projects”, I am just not sure how much C# you know)
Step 1) I would do an intermediate C# course, you can do advanced aswell. Reason being is there will be concepts like classes, methods etc, that you wil need to use in your games. One link if you want to check out is here:
if you don’t want to pay for it , there are free ones or what you could do is look at the content and just type it on google and learn that way.
Step 2) Take a course on making games like here on Udemy: https://www.udemy.com/courses/search/?q=unity%203d&src=ukw its pretty cheap. The point of taking a course if you have never made a game before this will guide you and you will learn new tips and tricks you can apply when you then make your own game.
3) Start making your own projects, whether its a clone of a game or your own, the goal here is to build some skills and have some fun at the same time.
I wish you good luck on this journey!