Thank you so much for this great amount of feedback!
Usually you should've been able to draw loops even when close to the castle, don't know what happened there. The loop detection, or rather the detection of enemies inside the loop, was a bit buggy, that's true. I relied a lot on Unity filling the drawn shapes with Polygon colliders, which doesn't work too well vor more complex shapes or irregular circles. Sadly, I didn't have the time to come up with a better solution, which would've probably been worth it in hindsight.
Thanks for playing our game, I'm glad you enjoyed it despite the bugs! :)