Onamatopoia- my poem

Onamatopoeia is a word which makes a sound like crash, bang and woof.
I wrote a poem called Lunchtime with onomatopoia in it. It goes like this:

LUNCHTIME
'' It's lunchtime!" said the teacher.
Everybody stomped the floor.
Then went out of the door.
After eating, the boys were playing handball.
Bounce bounce went the ball on the wall.
Boing! One of the boys hit the ball so hard
It flew through the air and landed on the grass.
After they picked up the ball,
a few girls including me started chasing them.
Thud, thud, thud went our feet.
He he ha ha! we were all laughing and having fun.
Everybody started joining in, in the sun.
Pant pant pant,pant- it was very tiring.
Duff! I didn't see the wiring
I didn't get hurt though
'cause it was very low.
Just then we all heard a loud, piercing whistle, whoooooooooo!!
We all rushed over to the shaded area to leave for swimming, stomp, stomp, thud, thud.
Mmmmmm mmmmmm My friend is humming a great tune.
Lunchtime ended so soon!