The Fievel area seemed so big to me when I was younger. But when I walked it before it finally closed, it just felt like a really well themed water slide with barely anything else to actually do around it. When it closed it had one slide open. A very small section of nets. Those foam things you walk through. That was about it. The rest were effects that no longer worked, like a canteen that squirted when you pressed on the front, but that's nothing compared to the musical frogs that are there now.
Fievel's larger than life mouse-sized props made it feel big, but unlike the Curious George's popular water play things, not too many kids actually utilized the Fievel area towards the end.
The new Shrek area extends out further than the original Fievel area did too, adding new splash swamp stuff where just paths were previously for example. And the meet and greet getting a permanent home is a huge win.
And just like Fievel, there's still a slide... but this one farts.