Edit: Updated impressions
Now that i had a bit more time with the demo and figured a few things, i've mad a few changes to my post.
For the most part the demo feels a lot like the the first lost planet but the graphics have been upgraded and there are a few nice new features.
Here's my feelings towards the demo:
Movement
I like the new sprint feature and the way you can cling to a wall or VS with your grapple, and we appear to be able to swim now (sort of how a dolphin jumps out of the water) 
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I couldn't put my finger on it last night but now i think what didn't appeal to me in the beginning, was how the characters actions feel more unresponsive than the last game. The transitioning between sprinting, rolling, jumping and grappling doesn't feel fluent enough an i think the animations between these actions need to be smoother and quicker. I would also be nice if you could do a running jump to clear a larger gap.
The 'hold button' feature used to pick up or swap weapons and exite/activate a VS adds to the sluggish feeling.
Hook
I heard that there would be some new uses for the grappling hook and it looks like you can now grapple to stuff (e.g. wall or vs) and stay clung on to it and then shoot from that location, which is pretty cool but i'm not sure if there's any thing else...
I was hopeing that you could grab weapons like in BC or have the ability to jump and grapple but i can't do either. I think you should be able to jump and then have a short amount of time (1-2 seconds) to grapple onto something.
I don't like the massive back flip that the character does if you grapple at the wrong point. It can lead to an aggravating death.
Controls and View
I'm not sure about anyone else but i hardly ever use RB and LB to turn and i think it could be used for something else and i also think that a better over the shoulder feature is needed.
I would like the option to use LT to go into an fine aim view where the aiming speed decreases and the camera looks straight down the gun sites. LB would then be used for grenades an RB could be used as the sprint button.
VS's
The new VS's are cool and i've noticed a few new animations for the old VS.
I'm not sure about the Lightweight VS with low armour, it seems pretty slow and i don't know ho to use the shield. I would be good is it was able to sprint.
If a VS is stood still you should be able to get on it without having the piolet power down.
Bugs
1. VS don't seem to explosion like in the original game. When your in a VS that exploded, you are taken to the respawn screen straight away without seeing you VS explode. Sometimes the button press B icon to exit the VS doesn't even appear and you can be pressing the button to exit but your character doesn't get out, the VS falls to the flaw and then suddenly you're on the ground unharmed.
2. Sometimes you can't pick up a gun. It's only happened once where there was a shotgun in a ditch - I walked over to it in my VS, got out to pick it up but I couldn't and the 'hold Y to pick up' icon didn't even show up.
3. The collision detection needs some work with regards to the salamander. It's hard work trying to get all the boxes from around a dead boss.
