Tidal Wave

The beginning is RNG restarting until the shrimps spawn in the ideal spots (the bottom three rows get damaged by waves so avoid placing there). Then you hope the second wave also spawns around there. 

Once you kill some enemies, it snowballs from there as you get more currency to work with.

You can put anything in front of a Crab or Starfish to prevent them advancing forward and attacking diagonally.

Pufferfish, Lobster, and King Crab can similarly be blocked with one unit to keep them from hitting multiple units.

Have multiple Sand Statues to create a chain of healing to help units placed in the bottom three rows survive.

A preview/confirmation button would be nice since I sometimes misjudged the hit box and placed a unit one tile below where I wanted it.

There aren't many different unit types/strategies like other tower defense games. But nonetheless I enjoyed the different enemy designs and figuring out how to turn the tides against the overwhelming waves of them.

I believe in Sand Tower diagonal killbox supremacy!