I went there with my 4 year old kid and his preschool. Good enough time-- saw a tiger pee through the fence on a tourist-- but the staff were a bit rude. I was standing by the "exit" while waiting for the rest of our party to come out and they yelled at me for reentering (by a few feet). It was obvious I had paid along with everyone else.

Also depending on when you go (or not) you'll want to wear mosquito netting. The bugs, not necessarily mosquitoes, are insane.