Yeah, I can agree with the first rooms feeling a bit more clunky, but it was only really the first area, and even then, a pool room near a spa-like area, close to a lazy river area that leads into a staff only "reservoir", leading into the slide area which starts off from the shower and locker rooms... It does feel pretty natural to me.
I wholeheartedly agree with wanting more abilities, there was that underwater vent, calling for me, and even though I was kinda relieved that I didn't need to go into it, I was still curious about what was on the other side.
Also, what's the deal with the door hidden behind the Lazy River sign?