I was using Obsidian for some time back then. It was pretty useful to associate/graph information to each other, and convenient to write in Markdown format. The learning curve may be a bit steep for some users.

The problem was the capturing and organizing of information took a lot of effort especially when the information grew in time. If you can really make something that makes capturing and organizing information effortless then that would be awesome.

Overcooked would be a good game to play with your wife.

Celeste is a good platformer. Shovel knight too.