Ask HN: What is the coding exercise you use to explore a new language?

What is a good sample program or project to work on to explore the primary aspects of a programming language? Something that can be worked on for a couple hours or days. Something that will give exposure to most of the basics of a particular language. Would love to know how people go about trying out a new language in this way.

My focus is usually from a game dev standpoint. I might see how quickly I can put together an A* algorithm on a 2d array. Or Conway's game of life as a similar, how easily can I process these things.

Should note I often work on 2d tile based games.

If I'm looking for problems I always like to try Advent of Code problems, it's a good chance to learn basic io, sample the standard library, and learn how to idiomatically handle common problems.

But before that I prefer to get a book and work my way through all the examples, otherwise I'm just making up what "idiomatic" means.

Redo a project you've done earlier with the new language (assuming it fits the general scope).

I try to explore a language using different problems every time. If you've already done a project or solved a problem, I think your previous solution will detract from getting a feel for a language's features and conventions by inspiring you to follow a certain pattern.

There's a pretty causal relationship between starting my unfinished side projects and me trying a new language or library.

I use advent of code to really dig deep into a programming language I sort of know but want to learn to use more. I plan on learning modern C# this way this year, it's been almost a decade since I taught myself the language at this point.