Hey, nice work! You have come a long way and had a small taste of what game development is. You have tipped your toe in programming and making art and started learning about game design. Let's take a quick summary of what we’ve just learned:
Many game programmer starts learning through tutorials and internet is full of those. But the "Hello World!" is the one almost everyone starts with.
A good way to get further with the code is the "Rock, Paper, Scissors" -game. It doesn't need any visual elements and can be run by the Visual Studio on its own.
Even in the modern era, some games are entirely text-based and are popular with adventure-genre players.
It could be said that a game's soul is the code, and the skin is the art. The majority of the games nowadays have visual elements and pixel art is one of the oldest art styles. During the course you had the chance to make your own pixel character and maybe in the future you will be making more pixel art.
Looking closer at games and us to understand why the developers did things this and that way and learn the design behind the game. When you have grasped the reasons behind the design decisions, it's easy to use that knowledge when designing games of your own.
Designing the game mechanics at the beginning makes implementing them easier during the game development when compared to coming up with them at the later stages. Adding game mechanics later might change the game entirely and could even make the game unplayable.