I dont know if an inexperienced dev like me should mention this but:
Making the projectiles deal the damage instead of just being cosmetic is with your current prediction algorithem a bit off at intersections
Mainly the [L] shaped Trackparts.
Aside of that, a Screen detailing (tutorial) of the UI would be nice. I cant seem to figure out what the 10 dropplets add to the gameflow or how to use them.
I'll look forward to the next itteration.
A few ideas that are from a biological standpoint possible,
Pumpkins may be useable as a slowing tower its a plant that spreads vines along the path maybe.
I dont know if you can itterate Surounding Pathtiles and add a overlayed texture from a tilemap that is being picked corresponding to the tile the tower is affecting.
Cacti could be great when their animation could send a spike.
However the Spheres might be great for mushrooms spores n all.
But i am lost in a rant by now so...
Good job
I want to see more