All style, no substance.
I must admit that I was a little disappointed with DOA4. I owned DOA3 on the Xbox and despite it's faults I did play it through to the bitter end to get all the hidden goodies.
Although DOA4 is graphically everything you'd ever expect from a game in this series, gameplay wise it just feels like a bit of a step backwards. My main bone of contention is the computer AI. Although initially quite easy to beat it quickly heads towards being almost infallible. It will almost always counter you successfully unless you pull out some outrageous combination of moves to keep it on it's toes.
As for the end of game boss! I mean, the Samurai at the end of DOA3 was pretty bad but this one is bonkers. One combo chain of hits can easily take two thirds of your health off your bar. And once again it will counter you at almost every opportunity if you are foolish enough to attack.
I don't mind games being hard, but when they are so annoyingly hard that you don't actually get a chance to learn anything from your constant beatings it starts grating on the nerves a bit.
DOA4 could have advanced the series but as it is I think it's taken a very tiny step back in terms of playability.