Here's where you can play the up-to-date version of the game:

https://www.numuki.com/game/unfair-mario/

Since most major browsers stopped supporting the Flash Player Plugin, it is probably one of the fewest places where you can play it nowadays.

You can find all the original Caillou Games right here:

https://www.numuki.com/games/caillou/

Hello,

While it's not yet fullscreen, however, it is the highest resolution that you can find online for this game:

https://www.numuki.com/game/wubbzy-s-amazing-adventure/

There is also an ongoing project for adding the fullscreen option as well. I can let you know once it is added.