[Cogito]

For those who haven't seen it before, throwing out nand2tetris and nandgame as another interesting journey from logic gates -> computer programs running on a CPU.

nandgame, in particular, is really easy to get started with and has been updated quite a lot over the year. If you looked at it a while ago check for new updates!

nand2tetris goes into a bit more detail around some things, I like it too but harder to get started with.

https://www.nand2tetris.org/

https://www.nandgame.com/

[adornKey]

Another game like this is TuringComplete. It's not free, but even more comfortable. https://turingcomplete.game/

[h3half]

I can highly recommend TuringComplete. If you know what you're doing the start can feel a little hand-holdy, but by the end of the game you have a functioning computer running an assembly language of your design and it's fairly close to an open sandbox.

Building up to that point having started from the basics was very neat