Well, this was a nice distraction. Was pretty easy to max everything, kill the Toaster, and really the last challenge was just the Final Boss which only took me a few tries to get his attack patterns down.
I like the charm of it though.
For those wondering why the coin matters, the coin can be used on the shopping cart to get it, instead of the wire cutters. I suppose this is an alternate way to get the cart for those who didn't realize where the metal cutters are. To be fair they're kind of easy to miss if you're not exploring every detail.
That's all the coin is used for though. Just getting the cart.
"How do you stun lifeless tower?" For the machine ones, it's LIGHTNING. For the other towers, people don't like lightning, so I assume it takes a bit of time (one wave in this game) to replace those now charred guards.