Many do not know but there is a large playground (with waterplay features!) on level 3 of IMM. It is outdoors and you can exit near Long Beach restaurant or Hai-Di-Lao.
The best thing is though outdoors, the playground is sheltered so the kids can play even when there is a light drizzle.
There are sections of the main play area that are suitable for both the younger kids and the older kids. The purple slide (in the first pic) is actually very high. So parents do need to be around to ensure safety of the younger ones.
Right beside this play area there is also a waterplay area. This area though is not sheltered so it can be pretty hot in the daytime.
The waterplay area’s water is turned on at certain timings of the day. So do not expect to go early before it gets hot. The water sprays only turn on at 10am. Not sure why they made it that way. The first time we were there at 9am only to be disappointed that the water has not started yet. Here are the opening hours:
Monday to Friday: 10.30am to 9.30pm (Closed every Thursday from 7.00pm onwards for events and on the first Wednesday of every month, except PH for maintenance)
Saturday and Sunday: 10.00am to 9.30pm
There is also a shower area at the playground. So it is very convenient if the kids were to play at the waterplay area.