The game will probably play and look fine, I just don't buy the crap that this is the culmination of pixel art as an art form as the site states.
I compare their work method to rotoscoping, because they work over another animated medium. The difference with rotoscoping is that they can already add style elements to the animation which should make it more believable, but still a lot more stale than traditional keyframing. They also make it look on the site as though they're the first people working this way, which is simply not true.
And they really really need someone to explain them how pants work and look, because after all these years, they still don't get it right.