Some of the critics are a bit extreme, but let's get a few things nailed down.
First, there needs to be some command for popping in and out of cover. Right now the controls feel very awkward, and the character himself feels oddly ponderous in his movement.
Second, the camera is indeed a nuisance more often than not. When you have to think around camera angles, immersion is already gone.
Third, the game play--while spiced up with 'mobile cover' essentially only had one thing going for it: gunning down stick figures. While most of the Sift Heads games make this a very visceral experience, this one feels sort of bland by comparison. Animation and gun variety need a serious boost, unless this is just a sort of 'demo' of a concept.
Decent ideas, but I think most people are disappointed because this just doesn't hold up to the quality standard that the series is known for.