Cataclysm: Dark Days Ahead
It's a time machine that teleports you to 3am the next day.
Sanmill
Basically nine man's morris, it's pretty fun trying to beat progressively harder AI. Each difficulty requires a different (better) strategy. It's like unlocking levels in a puzzle game.
Haha, this made my day :)
A whale swallowing the world.
I would just pick the value from the root of each underlaying balanced binary tree, easy.
If you create accounts on various sites with an email address on your new domain keep a list of those. If decide to let the domain expire you need to close the accounts beforehand, otherwise someone else can get access if they purchase the domain.
Also you will likely be playing for the domain forever, so just register/renew it for 10 years, maybe you'll also get a discount.
The recorder. It's easy to get started, there is a lot of good information online (look up Sarah Jeffery), and professional plastic instruments are very cheap. It also requires no special care and doesn't need maintenance, since it has no moving parts.
The downside is that in order to play larger recorders your hands need to stretch a bit, so I'm no sure if that is a problem if you have joint issues.
The other option is a hand ocarina, but it is very hard to even make a sound, even harder to make it clear and consistent. Also you need to play entirety by ear. It's a fun challenge, though.
Just buy a new SSD to install Linux on. If you decide to switch back just plug the old one in.
I quite enjoy Nix flakes for this. Only certain languages have good support though (C, Rust, Haskell, OCaml, ...).
The most important thing is that the codebase can grow without too much refactoring. Then you know you got the overarching design right. The rest then doesn't really matter that much. You can always rewrite certain parts when/if needed.
A good way to do this is by making the core really solid, this is called bottom up programming: https://paulgraham.com/progbot.html