I was here with my 2 kids on a Sunday afternoon. Hello Kitty Town is quite a small attraction, taking up only one floor in Puteri Habour Theme Park. If you buy a 2-park ticket, you can access the 2nd and 3rd levels where the Little Big Club is located. There you can find attractions based on Pingu, Bob The Builder, Barney, Thomas Train etc. Level 3 has the most rides such as mini-bumper cars, a mini ferries wheel and a helicopter ride. Level 2 has a large indoor playground with a slide and a mini-obstacle course
A walk-through of Hello Kitty Town, without taking part in any of the attractions, would take about 15-20mins. Most of the attractions are workshop-based where you can decorate your cookies and your nails and would appeal mainly to the younger girls. I was there on a Sunday afternoon and the queues were about 20-30 people long. Because of the nature of the activity, it took a long time for the queue to move. We decided to bypass all these decorative workshops and went straight to the Black Wonder attraction. It's the most interesting attraction where the participants had to solve several interactive puzzles.
The ticket is quite expensive for the limited attractions. Unless you are a great Hello Kitty fan, a much more fun and value for money option would be to go to Legoland instead.