We visited on a Friday so it wasn't crowded at all and we spent 5 hours here with our 4-year-old. The outdoor forest adventure area was my favourite as the weather was great and the autumn colours were beautiful. The tree houses were very cute and there was a lot to explore. There is a small river where you can do trout-fishing and have grilled fish afterwards (note that you can only catch up to 2 fish and to minimise the waiting time, the fish that you eat is not the one that you catch). The view from the giant ferris wheel was spectacular. The rides were simple but perfect for young children. Overall, we had an enjoyable time outdoors on a perfect autumn day and the free pass was well worth it (2,600yen for adults and 2,400yen for children discounted).