The teddy bear sticker:
This indicates that the game contains special modes to help younger children get more enjoyment out of the game.
From the Warlords manual:
CHILDREN'S VERSIONS
GAMES 21, 22, and 23 are special versions for young children. The
game play is slowed down considerably. All three games feature
ricochet(rather than CATCH), and all three have fireballs(slow balls).
The only difference in the three games is the number of players(4, 3,
or 2). Check the GAME SELECT MATRIX.
Atari did this with several other games including Berserk, Missile Command, Asteroids, and Yars' Revenge/Return.