Kids can do many things with slime. The most impressive part is that slime is different everytime you create it.
It changes shape instantly as you squeeze or roll it making it more interesting for the little children. For example, one time you stretch it giving it a long string-like shape, the next moment it can drip to the floor and breaks off.
The tiny hands can remain busy making their favorite forms like round, rectangular, elongated, etc. and can generate toys or merely play.
Again, slime can make farting noises, bubble up, spill, etc.