Big. Big. Big. Very informative for kids about the Indonesian culture.
Typically you need to spend a complete day or even two to enjoy the complete park features. It can be tiring, but, at the same time, it is very informative to kids.
You have a cultural museum, an architectural museum, an artificial river flowing through the park, a small 2 coach metro/tube running through it, plenty of ATM/ Cafeteria options, bird park, reptile park, beetle park etc.
There is also a Komodo dragon area here, where they are kept for real. Its quite scary, but, that is also one aspect of nature.
It's improving day-by-day as we can see in the latest snaps on Google.
Date of Experience : January 2009.