DAY 18
I am so good at making video games I fixed the stuff. Enemies now properly pick a random barricade to move to, reach it within an acceptable radius (just in case other enemies crowd around the barricade) and start "dealing damage" (currently this does nothing, but the Dealing Damage state does get set properly). I also fixed a bug where the player's railgun would pass through multiple enemies as intended, but only deal damage to the first enemy it hit.
Programmers talk about how sometimes you just have to bash your head into a problem over and over until you fix it. This is an amusing expression that's funny to imagine, however, not many people ponder the fact that bashing your head into a wall really hurts. Once you start working on trying to understand and fix an issue like the one I fixed today, though, you find yourself with oodles of time to ponder exactly how much pain wall-induced head trauma inflicts. But finally fixing the issue is pretty satisfying I guess.