Continuity mistake: When the other soldier asks Barns "where is your super soldier?" Barns is looking down at him with his mouth completely closed. It cuts to a close up before he looks up and suddenly he's gritting his teeth. (00:02:10)
Continuity mistake: When Captain America is found in the ice he is in a spread eagle position. In the next scene when he is unloaded out of the transport (still encased in ice), he is perfectly straight. (00:09:05)
Continuity mistake: In the scene where Thor hits Hulk with his hammer, he swings it, but in the next shot it shows him with his arm extended as if he hit him with his fist. (01:01:45)