Here is the full list of all 12 Iron Sea Defenders trophies - there are 7 bronze, 4 silver and 1 gold.
Launch 100 waves on one map manually
Sell 500 towers
Complete level when your castle has 1 HP
Sell 50 towers
Kill 1000 enemies
Build 50 towers
Kill 500 enemies with the secret weapon
Get 100 000 coins
Build 1000 towers
Kill 50 000 enemies
Fully upgrade 200 towers
Complete all levels with 3 stars