This was not a cheap production. Blizzard threw some serious bucks at this one. The animation appears to be the very latest Commercial Version of RenderMan. I can't even tell you what that costs because companies get individual quotes from Pixar to install it.
The reflection of the Bastion's bird friend Ganymede (yes the bird has a name but I don't see how Bastion could have named it) in Bastion's eye is particularly impressive and I am assured by a friend it would have been impossible five years ago. They also gave the bird a character without making it smile or any other cheap tricks. Mostly just body movement. Of course they've been doing the same with Bastion himself since before the release.
Emoting primarily with body movement and sound effects is nothing at all new. Nor is it new to do that with robots, obviously, R2D2 being a prime example of that.
However, Bastion is not an R2 tribute band. He appears of have been more than mildly influenced the Iron Giant.
They weren't really trying to hide it.
The Iron Giant is a sadly overlooked Brad Bird movie from before he hit it big with The Incredibles. It was the last of the great hand drawn animation movies, which I'm afraid is a big part of the reason it tanked at the box-office. It was a great little movie that captured the feel of 1950s science fiction movies. It was also surprisingly Red Pill.
However after Brad Bird got over the bar at Pixar, Warner Brothers dusted off the Iron Giant and made a special DVD edition with all the bells and most of the whistles. They even went so far as to finish off a scene that had only been roughed in pre-production but was cut from the final print for budgetary reasons rather than artistic ones.
Here it is.
I hadn't realized just how inspired by the Iron Giant the crew at Overwatch was until I saw their short.
I hope they find some way to get it in the theaters because I think The Last Bastion would have a decent shot at an Oscar.