Great job on the game! It's a cute game and fun to play. Bit tedious having to repeatedly start over because you're not given enough characters to start with initially, and it's a bit of a guessing game of what will happen.
Pathfinding is pretty tricky, so I wouldn't worry too much about that. What's important is you got the main concept down into a prototype. Though I think a nice feature as an alternative would've been to update the player's target position while the mouse was being held down, that way you don't have to keep clicking. I found myself spamming the click button while moving the mouse to guide the characters around.