This is a Hungarian folk song and its German translation. The German cannot be sung as the number of syllables don't match the notes but it's just there to give you an idea what the song is about. For those who don't speak neither Hungarian nor German here is an English translation:
Get through, get through, little green leaf
the golden gate is open, get through it
Come on, Come on, the shed collapsed
The shed collapsed, the cat was left inside.
On some websites you can find the translation with "hide, hide, little green leaf", but I think that bújj is the imperative form of the verb átbújik (go through) rather than elbújik (hide).
The game that goes with this song:
Two children form a little house or gate holding each others hands and raising them. (You can see this in the picture. But contrary to the picture children forming the gate hold both hands.) Other children hold hands and and make a snake. They walk through the gate while singing the song. When the "MACS-KA" (cat) is sung at "KA" the gate falls down and the child who is trapped inside will replace one of the children who formed the gate. An alternative version is that the gate always gets bigger and bigger as each child left inside the gate will join the gate and form a circle. Thus more and more children can be trapped inside and the game naturally comes to an end.