Space marines do not feel like space marines! I think this is the main reason this trailer is hitting a bad mark with so many people in my opinion.
Rewatch the trailer and have a look at the points below and let me explain. Trailer
(note - every part of the footage involving the force commander is just plain terrible for obvious reasons and so I won't go over this)
2:11 - What is with all the extraneous movements on the imperial knight!? It is a mech so it should just stand there when not doing anything, any movement in hulking armour is going to waste energy unnecessarily. The way they have animated it makes it look like it is a humanoid stretching it's arms. I expect mechs to behave like mechs and not humanoids, and so I have no idea what possessed them to give it all these unnecessary animations.
5:15 - Terminators running like olympic sprinters.... This doesn't convey the weight and power of terminator armour at all. Also the way the tactical marines are running around looks a bit too much although FAR better than the terminators.
7:12 - Again they have gone crazy with the Imperial Knight animations. Have a look at what it does before it fires it's barrage. There is simply no point to that extraneous movement. It's not as if the Imperial Knight needs to stretch it's arms after firing it's autocannons; it's a mech! Compare this to the cinematic trailer in which every movement is single minded toward the objective of dishing out the emperors wrath.
9:15 - Hopefully this one is due to the fact it is pre alpha, but the ASM combat attacks don't capture the feel of close combat. They are basically repeating two animations over and over again. This sequence is more similar to SC2 in style and not DOW. I'd like to see more elaborate animations with the odd sync kill performed.
9:23 - Some good points and bad ones here. Again the terminators look like they are far to athletic running like an olympic sprinters. Relic have done a really poor job of capturing the feel of terminator armour. On the plus side the combat animations look ok. THIS is more how I would like to see the FC behave with perhaps a few more special animations and attacks thrown in. Again the special attack is pretty stupid with the terminator needlessly swinging around the hammer a couple of times before actually swinging at the enemy. This just looks stupid and childish,
In summary I'd say there is a lot of promise in the trailer, but there are a couple of things which are really ruining it.
They haven't managed to convey the weight of the armoured units well at all.
Combat attacks are basically simple repeated animations much like SC2. There needs to be more variety in the animations, more weight to the attacks, and more sync kills (fast enough not to effect the flow of the game).
Some of the animations come off as simply childish which I think is where a lot of the cartooney criticism is stemming from (as I actually don't think the art style is to bad at all). The force commander is just plain ridiculous, and the Imperial Knight has far to many silly animations which serve no purpose, and that terminator special attack is needlessly silly.
(There are a lot of things which I did like though, but I wanted to provide some constructive criticism in this post which is why it will come off more negative than I actually feel about the game)