Basic Computer Games (ported to C#, Java, JavaScript, Python, Ruby, VB.NET)
github.com
github.com
I tend to think that simple, self-contained programs and games like this can be a nice onramp to computing. Also it's remarkable that a very small program – such as these BASIC artifacts from the 1970s that managed to run on something like a 1MHz, 8-bit microcontroller with a few kilobytes of memory – can still implement an (arguably) interesting and/or fun game or simulation.
It can also be a fun exercise to write the same program in different languages and compare the results.
I'd still like to see a "write code" button in browsers that opened up a tab where you could easily write (JavaScript) code like this (and maybe even simple graphical games as well, e.g. with a simple canvas/svg + audio + controller API.)