Time versus access versus weather versus energy!
A detailed listing of the options available to children in Singapore.

Snowboard, ski... why, have a snowball fight!
 Snow City.   Ice Skating.

Science, like you've never understood it before.
 Singapore Science Centre.
 Singapore Discovery Centre.   Museums.

Easily - and extensively - accessed.
 Parks.  Gardens.  Nature Reserves.

A world-class Zoo, a Night Safari, Bird, Crocodile & Reptile Parks, the Underwater World.
 Jurong Bird Park.  Night Safari.
 Singapore Crocodilarium.

And take your picture with them too!
 Underwater World.