The funny thing is I used to use the term "human construct" instead. But it was too confusing to people. And I kinda have to wonder, if you digitize a human, should they be considered artificial at that point or are they still human. Or is AI consideration based on how the Intelligence arose in the first place?
So I'm still not sure what the best thing is to call them.
The easiest way to beat the medics at the end of the level 23 by placing sentries with splash, fork, and linker. Otherwise, leave them alone until the end of the level.
I actually had a lot of suggestions to make upgrades share between towers. The problem with doing that is it encourages clumping up all your towers in one spot. It also leads to some extremely overpowered towers that then need new powerful enemies, as well as making it more difficult to balance.