I only see two things wrong here. One, your set-up is inconsistent, and is usually with your hips a bit low / shoulders not out in front of the bar enough. This variability is what causes some of your lifts to go forward, and some to go backward. Note the very first rep you shove the bar forward with your shins. This is wrong.
Second is your stance, which is wide. Your stance should be narrower (prob. about an inch) with toes turned out.