Allaire is one of those parks that your first visit or two you are wowed but beyond that there is no real reason to visit again. The train is fun to ride once and they have a tiny little gift shop with little trinkets and such. It's interesting to walk along the row houses and village to see the old buildings inside and out. They will sometimes have actors working the area and walking around for you to interact with. We've visited while real couples got married in the old Church. The trails outside the village area are rather bland and in some sections often overgrown and hard to follow.
There are picnic areas and play areas but they are not often occupied. The park is pet friendly but you will obviously not be allowed in any of the buildings or the train.
The park boasts plenty of events but several times these events will be canceled and they never update their website. I've complained about this to park officials before and their only answer is I should have called before I came that events can be canceled at a moments notice. Luckily I only live 30 minutes or so away so it wasn't so bad but for people who may be traveling from over an hour away that is definitely the wrong attitude for park officials to have with their guests.
After a visit or two you've basically exhausted all the park has to offer and there are nearby parks with nicer trails