Eh, most critics seemed to either not get the joke (that it's supposed to be exactly like a cartoon that wasn't that good in the first place), not get the message (thinking it was hypocritical for a big studio movie to attack big business when really it's mostly reflective of the directors' frustrations with their system and philosophy on making change within the system), got headaches from it (understandable; it was a bit too long for such a packed movie), or still be angry towarRAB the Wachowskis for the Matrix sequels.
Give it a few years and it's gonna be a cult classic. I'm pretty much sure of it. It's already been shown to be somewhat ahead of its time (when it first came out, they thought the economics stuff didn't equal convincing enough villainry, but with Wall Street lately...).