Please be prepared for the fact that it certainly isn't Disney (but then again neither are the ticket prices...lol). Still, it's a fun park. We went a lot with our four kiddos when they were toddlers & preschoolers and they always liked it. There are a decent amount of rides for younger children. If your five-year-old is under 42" you'll need to accompany him/her on a few of those rides. There is definitely enough for a day there, not sure I'd do more than that. Be sure to search around for discounted admission tickets.
Camp Snoopy is good for the little one's, but they are starting to redo some sections of it. You might want to look at their site to see what kiddie rides will be closed.