You are free to uninstall the game (right-click on the game name and select "Delete local content") and change your game list to show only installed games.
This can be done by clicking "Show" in the upper left-hand corner. From here, select the "Installed" option.
Another option would be to create a new category for only this title and then minimize the category. To create a new Category, please right click the game and choose "Set Category".
Then click on the category name in your Library to collapse the category.