Paid promotions?

[Skulletgirl]

It's pretty common from what I know to receive gifts and or payment for your time. The product itself of course needs to be free for you to review and the gift/cash is your payment for the time, effort and publicity you provide

 

[Voov]

Been in the game industry myself, and this happens quite often, since game developers are desperate to get the word out about their game, and Youtube seems to be an easy platform for it. Normally though, only a key is given to the channel to review - if they have sent you something else, I don't think it should be much of a problem either, they're definitely thankful you agreed to spread the word about their game, but you should make sure to explicitly state that in the video.