Ostrakinda

Split into two teams standing on opposite sides of a line drawn on the ground.

One player tosses the two-toned shell into the air like a coin flip.

Whichever color lands facing up decides which team must immediately turn and run, chased by the other team.

Chasers try to tag as many fleeing players as possible before they cross a safe line at the far end.

Tagged players join the chasing team, and the shell is tossed again to start the next chase.