Three difficulties, one defense job
The game lists Easy, Medium, and Hard. It does not publish separate wave counts, damage numbers, or coin multipliers for those modes. What is published is the stage rule: clear a stage and the sea pulls back, the beach gets wider, and the waves get bigger.
Use the mode you can currently hold, then move up when the same defense shape survives with time left to repair.
How to move up
| You can already do this | Reasonable next step |
|---|---|
| Finish a packed sand wall and trench on Easy | Stay on Easy until shovels replace the toy spade |
| Hold several Easy stages after the beach widens | Try Medium with the same wall shape |
| Cover the wide beach and patch during the wave | Try Hard, and bring late materials when they are unlocked |
| Lose because of a gap rather than wave size | Stay on the current mode and fix the line |
Hard does not change the controls. You still dig, pile, trench, pack, and press START ROUND. The difference is that a gap you could ignore on Easy is large enough to lose the town.
Rewind
The description offers a free Rewind for joining the Beach Club group. It does not explain the button-by-button effect of a Rewind. Treat it as the listed group reward and learn its timing from the in-game item, rather than spending it on the first small wave by habit.