Hey, I noticed your game because we used the same asset pack for our gamejam. I really enjoyed your game. I played it for like 3 hours and all the way to the end :D
This was my comp at the end:
I had some FPS issues starting at wave 5, which seemed to increase when all units were walking. When I placed a wall and all units started attacking the fps issues were not that bad.
I noticed that you can control the enemy units when you have a free way to your castle. When I wanted the enemy to stop and fight instead of moving forward I would place a wall for a short amount of time and afterwards delete it to get them to move forward instead.
I also really like your user interface. You did a way better job with the assets than I did.
Really nice game! :)