There are different-colored squid on some levels, and they slide up one tile with each move.
You need to make matches with them or explode power-ups nearby to collect them. Lightning bolts clear all the squid of the same color along with regular pieces.
You also need to ensure the bottom row (where the squid spawn from) is kept entirely clear of boosters, crates, tyres, dirt blocks, and other obstacles. Otherwise, the squid will be blocked from spawning.
IMPORTANT NOTE: You lose if even one squid reaches the top edge of the field.
