If I play a demo/beta and really like it, then that's going to be a much bigger factor for me than any review. Soul Sacrifice and Dynasty Warriors Next got mediocre reviews, but I loved the demos and bought them anyway. And really enjoyed them.
With reviews, the kind of game and the developers/publishers involved determine how much weight I put on them. With fighting games, I find that a lot of professional critics don't know what they fuck they're talking about half the time, so their impressions don't mean as much. If it's a genre I don't usually play much, though, then the reviews play a much more important role. Gameplay footage and word of mouth are also important.








