NTA since there was an agreement before. Yes, it may be"only a game" but it's still a boundary that has been established and then trampled. It is about respect and it's not enjoy a week off the Switch is going to hurt anyone.
When it is a totally shared console and game then I think it is nice, albeit a little OTT, to take it away.
If the console was given to her and she has the expectation that she's primary possession, and she's sharing it with you so you can play Animal Crossing, I would believe this punishment foolish.