Hi
My husband and I (no kids) stayed there a couple of years ago and I give it a big thumbs up. There is an indoor (small) water park. My memory is that there were 2 water slides, a wave pool and a kid's play area there. Plus, as others have already said, it is centrally located to the mall and other things in Hyannis and it was a nice hotel (i.e. nice rooms) - plus the restaurant on the property was very good (heath n' kettle).
I would definately recommend staying there - especially if you are going with kids - the pool/waterslide area is great. My memory is that at night they have a big bonfire outside too.
I think you will enjoy it.
Have fun!
-Nicole