I have to agree. What happened? We get great animation in the first episode and as the show goes on, the character movement gets stiff and they would constantly use stock footage which become so obvious that it's cringe worthy sometimes. Especially when you see characters in environments that look nothing like the setting they were just in.
Sick of threads "Megan Fox should play this!"

I didn't think the animation was that bad in the later seasons.
"Time to die! Like a man!" Venom Spider-Man Web of Shadows

Season 1 had overall smoother and more consistent animation. Though, I think the overall design of Peter after the first season was better.