There are very few companies who will actually continue to co-operate with you after a negative review towards one of their products. I tend to find that reviewing products by dividing reviews up into two 'categories' of target audience, you achieve better results. By saying
This game is brilliant for those who don't care about the details of , but just want to kick back and relax with friends on a Friday night
you make it look good... and then simply follow it by
For those who are addicted to their games, you might want to wait until it hits the bargain bins.
That tends to mean you can average up your rating a bit... and no-one tends to notice - and your readers get to know your strategy after a while, resulting in 'accurate' reviews whilst keeping publishers happy.