There is also a paid tier for Stadia which does come with some added perks and benefits, one of which includes a free base copy of Bungie’s Destiny 2 game. However, Google has since announced that starting the 19th of November, Destiny 2’s base game will be free across the board for all Stadia users, including those who are using the free tier.
According to Google, “This play for free version of Destiny 2 begins your legend with a large variety of activities – from cooperative quests to competitive modes, challenging endgame activities, and more. Even if you’re not a Stadia Pro member, you’ll be able to take part in the core Destiny 2 experience.”
It should be noted that this is just for the base game and that if you want the expansions, you’ll have to buy those separately, but it could be a great way for you to try out the game if you haven’t already, or try out Stadia as a service in general.