We went to the fun park in Breckenridge - Chase had a great time. I highly recommend the day pass, it is expensive but worth it. The park was perfect for younger kids. The Alpine slides are really fun and aren't scary at all, even for ride wimps like me (except I hate chair lifts).
(Chase was grumpy in the above picture because the people in front of him were going too slow...)
B and C tried the Gold Coaster but I skipped that one. Our friends did the ziplines and said they were fun but those do have an extra cost and take an hour to do and have schedules times.
Chase was a little afraid of the bungee trampoline but I am proud of him for trying it.
The only negative was the price of food - it was like being at Disney. It was kind of ridiculous but you could easily bring your own and avoid that problem. Oh and be sure to reapply sunscreen regularly (we ended up with some crispy critters around here).
Overall it was a great day!