Gamespy have posted a Review of NFL Blitz 20-02. Here is a snippet of the review:

In Blitz a first down is 30 yards, not 10, which is way too easy. In addition, there are no penalties. None! Get used to seeing things like rampant pass interference and many, many, many, out of bounds line violations. Also, Blitz TD will be called even if your opponent catches the ball in the back of the end zone and lands out of bounds. This will have you activating your blocker to nail the receiver before the ball even gets there. You actually have to interfere with the pass. But again, we're only working on the gut level here.

Strangely, Blitz 20-02 adds one more player to the field than its previous incarnations, yet still doesn't field the 12 players the NFL mandates. This extra man is called the "Impact Player," who basically functions as the one guy you can assign a specific task. He can cover, drop into a zone, provide man coverage, or rush the passer to support a blitz. This feature adds a lot to the gameplay, letting you alter how plays unfold. Hits are brutal and late hits are encouraged; the kind that would make Joe Theisman cringe.

You can read the rest of the review here.