The faces wouldn't be as funny even if they were computer animated...
That's why you work even harder on movements and stuff.
LegoShark, I've been working more on a livelier type of animation that I think would suit physical comedy very well. I think you should try exaggerated movements; take The Adventures of Eddy and Jane, Episode Eight. During the chase scene on the pirate ship, Jane and Igor both throw open the doors leading to the captain's cabin; notice how they seem to lean back really far as they finish throwing open the doors, and hang there for a couple frames.
Even if a character isn't animated, you can still exaggerate them. For example, if you have a guard, holding a spear, shield and everything, you could have them lean back somewhat instead of having them straight.
This is something I would like to see more in Brickfilms. We've kind of fallen into a robotic-ish movement for our characters, which doesn't look so out of place in serious films, but hinders comedies. It's refreshing when a film like The New Neighbor or Ben Cowell's 1234 comes along, partially because they don't follow the robotic movements.
Also try filming yourself doing an action, then use that as a reference while animating; this is what most professional animators do. I have yet to try it myself, but I can see where it would be helpful. I think if you know exactly how the movements are going to be done, it can be easier to exaggerate them.
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