Have kids quickly say their names to the group (the faster the better).
Then form two teams - Team 1 and Team 2 - and have them face each other from opposite sides of the room.
The first person on the right end of Team 1's line call out the name of the person on the right end of team 2's line. If he or she correctly identifies this person, that person must go to the left end of Team 1's line. But if they incorrectly identify the person, the person from Team 2 must say his or her real name and move to the left end of their own line. Then have the person on the right end of Team 2's line call out the name of the person on the right end of Team 1's line and repeat the process as before.
Continue playing until everyone from one team has been captured by the other team or until it's obvious everyone knows everyone else's name.
Teammates may not help each other. Anyone who does must go immediately to the left end of the other team's line.