Kabaneri of the Iron Fortress 1
The design of the fortress is killing me. Giant moat(?), awesome. Huge walls, great. Draw bridge, nailed it. But with all that trouble, they should have also gone out of their way to make the area where they process the train a completely separate zone outside the main walls with drawbridges at both ends as a buffer. It looks as though there's no protocol for the bridge going down other than seeing the train, so it's crazy that the idea of it completely overrun never occurred to them as still being able to move.
The train design is killing me too. Besides completely sheer walls and maybe sharpened prods jutting out, it can't be too difficult to make a moving, flat surface literally unclimbable. Instead there's a bunch of open platforms and footholds inviting them in. Not even sure what those holes serve other than to shoot out the Kabane climbing that are mostly there because the holes are there in the first place.
I'm guessing the significance is fleshed out later, but it's not really made clear the reason of needing to destroy the heart to ultimately kill the Kabane. Not sure what that accomplishes versus destroying the head, so MC making a special weapon, which just seems like a more powerful gun rather than anything uniquely tuned to the Kabane, felt flat.
The violence lacks a shocking/interesting twist to it. Whereas Titans act erratically in combat and kill in various ways for seemingly no reason (which is in and of itself disturbing), there's no ambiguity to the Kabane and the extent to which they can kill is extremely limited. They kill to propagate, and if they spot prey they go for it. The rules of having a dumb force versus a somewhat coherent force seems like it'll leave much less room for variety in how encounters play out.