You might have to double click the flag to start P1: Left & Right to move, Up to hide, Down to crouch. P2: A & D to move, W to hide, S to crouch. P3: J & L to move, I to hide, K to crouch. P4: F & H to move, T to hide, G to crouch.
This game heavily relies on sound cues. Keep your volume high. Credits to LSPLASH for the original game & sounds.