This is one of our DD's (6) favorite attractions in all of WDW. The only immersive effects, as mentioned, are the bubbles and the water that squirts from Fozzie's flower (not much compared to MPH).
There are some loud noises, but one recommendation for this attraction and a lot of others is to use ear plugs with your children. This way, the loud noises are muffled but they can still hear everything else. The earplugs work wonders with the nighttime shows as well (Wishes, Illuminations, Fantasmic). Definitely use them for a more enjoyable vacation!