Looking Stupid
Questions: What do enemies do when they're not attacking? What do enemies do to avoid looking like they are uninvolved in the combat?
God of War: Enemies in the far group just stand around and look relatively uninvolved. But they're zombies, so it looks OK. (Personally, I believe the popularity of zombie-killing games is partially fuelled by the lower AI expectations-they're supposed to be mindless, so game development is easier. That, and zombies are the only thing as fun to kill as Nazis.)
Enemies in the far group would occasionally play a yell/cheer animation that seemed more involved, but it was fairly infrequent. I get the feeling that they noticed this problem near the end of development and made this animation to fix it, but it turned out to be just a bandage.
Mark of Kri: Enemies in the far group are constantly moving, mostly just sidestepping in a ring around the player. This makes them feel active without really affecting gameplay, especially since the motion is centered on the player character. The close enemy stands still a lot, but his animation and facing make him seem to be watching the player character and waiting for an opportunity, so it feels appropriate.
Genji: Enemies are always moving in a slow, pacing, stalking motion. It does a good job of making them appear involved in a samurai-appropriate way. But they tend to get stuck on environmental objects and appear to moonwalk, which ruins the illusion. If their pathfinding had been able to better account for obstructions, it would look a lot better.
Prince of Persia: Enemies are always moving, which makes them feel involved, but the animation looks twitchy when changing between AI states, which ruins some of the effect. If it were smoother, it would feel even better.
Ninja Gaiden: Enemies mix side-step movement with standing in a fencing pose. The fencing pose does a good job of appearing involved even when they're not moving. My expectations may change a bit for ninjas, as I expect them to be controlled and cautious in their motion. A stiff animation makes sense for a ninja.
Heavenly Sword: Enemies use a circle strafe walking motion to appear to be doing something. But there are times when this behavior falls apart, and enemies strafe in a circle, or stand in place, or run to get to a seemingly random position. There are no occasional cheering animations.
Conclusions: Having enemies pace and sidestep when awaiting combat feels good. It makes the character feel active and also masks small positional changes without having to pop out of a standing animation. Occasional animations like the yell in God of War don't really help much, since there are still long periods of just the base animations.
Getting the right feel for the base animation helps a lot-characters who appear to be focusing on the combat instead of just using a generic standing animation feel much better. And tweaking one animation is a much simpler solution to execute than trying to fix this with complex AI changes.
It was interesting to note how many little bugs ruined otherwise good animation. That may partially be an artifact of my methods breaking the system or my overly analytical approach to the situation, but I think a bit more playtesting and review of content once it's actually in the game code would have helped many of these games.