I started playing this game right after playing the first two and I guess I was just kinda tired of Prime for the moment. Hence why I still didn't finish this one. I do think it's good though, for what I've played at least. The motion gimmicks aren't half bad, they don't really disturb the flow of the gameplay. The new emphasis on story and more of a cinematic direction are kind of... uncharacteristic for this series. It feels like it's stripping away part of Prime's unique character to make it feel more like some other sci-fi shooter. I don't know about this one.
I do appreciate the more linear level design. What for some is a huge turn-off, for me is an absolute plus. I don't like the metroidvania structure, so I had much more fun playing through this than running around aimlessly or following a guide.
I will come back to this game. When I have the time.