The pixel art caught my attention especially the ocean waves and its animation, they look well made.
The game design is interesting. I like the idea of waves damaging the towers at front. However it needs warning indication how far the next wave can travel, for now it is just the whole 3 rows. Also this can potentially add depth to strategy. Thinking of different wave patterns per turn and player have to reposition the tower if necessary. Or maybe a tower or item that benefits from water.
I won at first try with first tower and healers - too easy. But I understand that balancing is hard especially in short time period. And please, the sounds are really loud and annoying.
I guess that's it. You did a pretty great game.
Make the coconut tree shoot some coco.