Someone made a cool
graphical comparison video between E3 2014's build and the current one:
To me there's definitely an improvement. The lighting has been changed to make it actually suit the scene, the main character's model is higher poly (his bald head isn't as jagged anymore, see 1:23), lots of objects have more detail, there's added lens flare in one of the cutscenes.
Yes, it's low budget, but some effort's clearly gone into it. If they really didn't care I doubt the trees would be swaying about when that helicopter lands. But to cherry pick screenshots and call it a PS2 game is unfair given the tech involved in general. "Low budget" is still how it'd describe it when it's looking at its worst.
Generally I agree with memecomplex's posts. So far any impressions are based on the early single player campaign, yet some sites and people can't stop bashing it. Then again, Nintendo of Europe didn't exactly handle this in the smartest way -- if this was a major Nintendo release it'd probably have had a press event at NoE/NUK offices where players are only restricted to play select segments of the game, and online would likely have been encouraged. I remember stumbling across an online Splatoon Miiverse community for reviewers before that game launched, for example.
If the online turns out to be good, then they've truly messed things up, as the damage has been done.