Drag two matching coral together to merge them. Each merge makes something much stronger.

Coral next to coral fuses after a few seconds: +20% power per link to a different coral, +5% to the same kind. Moving or merging a coral breaks its links.

More polyps: every wave you clear refills you. In later reefs, every few creatures you stop gives a polyp. Fuse a reef of 4, 6 or 8 coral for a one-off bonus.

This demo records anonymous play data to help balance the game.