This is the campground I grew up going to. It is a fantastic park with a beautiful beach. I've visited many dune parks along Lake Michigan, but there is a grandness about these ones that I haven't found elsewhere. If you are looking for somewhere to be active and climb and hike the dunes, few places beat here. The beach is also a wonderful place to be active. The water is the perfect depth for splashing around or swimming laps. Dogs are allowed on the far side of the beach too!
There is access to the dunes from the campground. It is a fantastic dune to climb, but is very steep so be prepared. Once at the top of the first dune, there are lots of dunes and sand bowls to run down and climb back up. If you are feeling super adventurous, you can hike across the dunes from the campground to the beach. That is an intense hike and I don't recommend taking kids or dogs (especially on hot days). I was a kid when I did it last and I vowed to never do it again. It might not be as it seemed then, but better to be prepared. For those who want to save their energy for the beach, you can drive there. The parking lot is huge.
If you are just looking to relax at camp, Warren is still great! The bathrooms are always clean enough and the showers have warm water. The campsites are well spaced and many of them are shaded. There are lots of little trails throughout the campground to get you to the bathroom quickly.
I have fond memories of playing on the playground as a kid (and it still looks fun now too). There is a nice field to play catch in as well.
The only downside is the price. Michigan state parks are always pricey.