Stardew Valley. It’s a cozy farm sim with lots to dig into if you want to at your own pace (it is not uncommon to play the wiki open) The same save file can be used for single player or multiplayer
(local or online).
Castling itself (as a single move) is a 17th century balance update. Before that it was done as separate moves. But the only reason castling became a thing was because the Queen and Bishop were buffed in the 15th century allowing them to threaten more spaces. This made it more advantageous to fortify the king’s position than to have him flee.
Kids are sticky. lol.
Crack that hori open and clean it. The top shell and button caps can be washed in the sink if they’re just plastic. That’s probably where most of the sticky is.