This patch basically includes an extension that locks the mouse within the space of the game window during the mini-game where you help Grandpa sound out/pronounce a word.
GMG! v1.2.2S Patch
Source: Steam Community (opens in a new tab)
Build and release context
Steam update times within 24 hours of this post. Matching dates do not confirm which build it describes.
Build 9247418 · public branch
Steam updated · First observed