For me if it isn't free it isn't a demo =p
Unfortunately I don't have interest in Stadia so these aren't the games that would entice me to test it.
Well, but it *IS* completely free. Just open the links in Chrome and you can play them.
I know people don't like the idea of Stadia and don't want to sub to it or buy games, but if there is a free demo of a game on there it is completely free as you said. All you need is to open Chrome and have a gmail account to play. I'll be playing the demo, and if I like it I'll pick it up on Switch.
You do not need a game console or a decent PC to play this, just a good internet connection with Chrome browser and a gmail account.
This is actually the one thing I can give credit to Stadia for, is when they have a demo it is COMPLETELY free. Think about it, if a demo is exclusive to PlayStation but you don't own one, then you're either left out or you need to spend upwards of $300 to play it. Now with that said I still think demos shouldn't be exclusive, I'm just saying that if a demo is on Stadia then it is completely free.