Claim the Daily Spin and daily rewards, then build a continuous packed sand wall with a trench before you press START ROUND. Spend the coins from waves you hold on the next tool you can actually use.
Are there working Stop The Tsunami! codes?
No active or expired code strings are confirmed for this game. Check the session after updates, and do not enter strings copied from unverified lists.
What is the free Rewind?
The official game description says joining the Beach Club group grants a free Rewind. The exact group page is not named in that description, so use the join prompt inside the game.