The children have been creating avoidance games in Scratch. They had to code their player sprite to be controlled by keyboard inputs and code the enemy sprite to move in some random way. They then tried to make the player sprite disappear if it was touched by the enemy sprite. Some children also added code to implement extra lives, a game-over screen and even a running score in their programs.
You can play some of the children's games here: https://scratch.mit.edu/studios/34094512