First things first : great job. The game is fun I spent a surprisingly good amount on time on that one and I think I'll try it a bit more when I get the time.
Now for the criticism
the plus - the visual assets are simple but good, the ghosts are quite fun to look at, the animations are fluid - the planting and harvesting part is fun - your character controller is pleasing (the diagonals makes you go faster be careful) - the time ghosts takes to turn and attack is a good idea to balance the game
the minus - it took me 5 minutes to understand how to play the game. there is no asset when you plant something, only when your harvest them. interacting twice with an empty spot to get something is hard to understand with your tutorial running as the ghosts spawns. - the towers are surprisingly weak. they cannot even take a ghost 1 on 1 and takes too much time to make you end up with an army of ghosts and nothing you can do about it. ammunition management makes the whole thing even worse. - no music. you can try little loops with beepbox.co if you want
other - the strategy I used made me somewhat immortal : packing the ghosts and going back and forth between 2 plant spots planting turrets or ammo. with the time they take to turn around and their attack animation they cannot hurt you. - no zqsd but we're used to it
the game balance is not very good, there is no time or scoring so no real point to keep playing but the game still is fun, quite good looking and works very well for a 2 day jam so once again good work and have a nice day