Regarding Rex, I've got it set up, and I'll be testing it during runs. Seems pretty cool, so far, though.
For Reanimator, overall seems super cool, I haven't beaten it, yet, but that's fine. Those walls that seem to grow when you're near, very cool, but for a few runs I thought that these would damage me or something if I got near. Purely cosmetic?
I got one missing image error....missing ZombieMechTorso2.
When you use the teleporter to the boss, the shot clearing effect that triggers can look a bit janky as it affects your own shots. It's like your gun has stopped working or something. This is the normal bevaviour of the teleporters, right? If so, I need to Mantis that.
Not the most useful feedback, heh. I'll keep testing. Seems an enjoyable boss to me.