Please correct me if I am wrong. Don't I need to still buy a Stadia controller to play these games, even if they are otherwise free?

Anyway, they look like decent enough games. The Pac Man one looks the best to me and the other 2 games look like they are worth a try. However, I can't say that any of these games has me super excited. For me the issue with Stadia, and streaming services in general, is that my wallet is not the limiting factor to playing games. For me, it is time. I already have more than enough games to play, but I don't have time to play them all. While I like cheaper gaming, that is not my first goal. My first goal is to find the games that I will enjoy the most and then play them. Stadia doesn't have anything that would compete with Breath of the Wild, which is the game that I like most from the current systems.

I'm going to buy the game and own it on a console.

Yeah, 60€/$ for an early access game is quite steep. For the multiplayer, apparently it works cross-play, though I haven't tested multiplayer at all: https://www.siliconera.com/cross-play-and-cross-saves-baldurs-gate-3/

Stadia supports a lot of controllers (Playstation, Xbox, Switch) and Keyboard+mouse. Stadia controller is the only option reducing lag though, as it directly connects via Wifi with the Stadia-server instead of going through your computer first.

https://support.google.com/stadia/answer/9578631?hl=en

I personally am more interested in Humankind, as this looks like the right kind of complex strategy I like, but yes, Pac-Man looks like cool Arcade action in an interesting multiplayer mode. Fenyx actually takes a lot of inspiration from Breath of the Wild according to reviewers, with exploration and mobility option while retaining fighting controls similar to Assassins Creed. I will surely give it a try, as I strongly consider to purchase it for the Switch later this year.

That is actually the cool thing about these demos, you can try the game, regardless of the platform you later on wish to purchase and play it, as the Stadia demo needs only Chrome and a decent internet connection. I plan to buy Fenyx on Switch, but will surely try the demo.

Thanks for the link.   After watching their initial presentation, I got the impression I needed a Stadia controller in order to play any of the games.  I think this is a marketing fail.  I don't think it is just me, because I did a search for Stadia ads and this is the top one that came up.

The ad makes it seem like you need their controller to play Stadia.  If I can just use the keyboard and mouse on my laptop, then that is a whole lot better.  They should really be focusing more on advertising the convenience factor of it while they are actually focusing more on the technology and the costs.  My laptop sucks, but I just learned I could play Stadia on it without needing a special controller or anything else.  I don't have a PC gaming rig, but I don't need one.  I don't need their controller either.  They should be advertising this more.

I agree, that isn't made clear enough. Funny though, Google seems to realize this, they just released an ad focusing on that a few days ago, aptly named "You have what it takes":

https://www.youtube.com/watch?v=Seo7l6OcPVo

That's what I'm doing. I want to buy on switch but why not try it out. But they are making it really hard by not allowing it in my country for some stupid reason.

That is a better ad, but it's still too subtle.  They are using the Stadia controller in most of the shots.  It would be better if they hit us over the head with the idea that we can use any controller or a keyboard and mouse.  This ad is a step in the right direction though.

After watching the trailer of Fenix I got more interested.