This is a survival dungeon crawler. Dangerous artifacts of great power are on a fire sale, yet the vulnerability of being without a wand is enough to give pause.
I did not make it to the end. The rangers managed to continue sneaking arrows through to me.
The game does use NavigationAgent, and will benefit from a greater understanding of it. Both the Rangers and Warriors have a great tendency to get stuck on corners, mitigating the pressure they're supposed to have.
The artillery mages, however, are a bright spot shining in this one. The visual noise they create opens up space for the rangers to sneak in those arrows. The warriors? Not so much.
I have a feeling that even you believe the overloading mechanic of the wands may need a little bit of work. If you did not believe so, there would not be so much availability. In my opinion, what you could do is make an aggro range for the mobs while you don't have a wand. Once you do, however, it's all fair game. When you're defenseless, you need some other way to progress through, or the mechanic, as it is, won't get proper utilization.
Continue with this project, and experiment with the used tools a little more. Refining this project, in my opinion, is your best path for growth.