BackFire
Blood. It's nature's lube
I'm responding because your criticisms are stupid for the most part.
the AI is fine, your one bug that you found doesn't change that. Enemies take cover, they flank, did you play it on casual difficulty? If so, try raising it, hardcore is much more fun.
The game is slow because that's its style, the developers made a concious choice to make a slower, more methodical and strategic game. It sounds like you went in thinking it would be like Halo or something, which again, had you taken a few minutes to actually read something about it besides the hype of "OMG THIS GAME IS TEH AW3SOME!" then you would have known this. This is not a flaw. This is like someone climplaining that Halo is fast, and that the game sucks because of it. Just stupid. It's a decision the developers made, and it works.
What's with this stupid logic that for a game to be next gen it needs to have more players? A low number of players is beneficial for this style of game, and I'll tell you why. Since the game uses the "you die and your out until next round" type of multiplayer, having a low number of players makes it so the rounds are short, so you never have to sit out for too long. It also makes each kill important and meaningful. In games of 20 on 20, one kill doesn't mean shit because there's still so many players on the other team, in 4 on 4, though, one quick kill can be the difference, so everyone actually tries, and each kill means something as a result.
Grenades certainly aren't useless, in fact, they're very useful in certain spots, you need them to close emergence holes sooner then they would on their own. And in Multiplayer grenades are a godsend.
Sprint button is not a flaw, it never makes you use it, it's just there if you want it, you hate it so much, don't use it, won't change a thing. It has its uses, and they're plentiful, your illogical distain for sprint buttons in games is really strange to me, I don't get it.
Too easy to be killed, eh? Try taking cover, this isn't Halo, you're not going to bunny hop and run in circles killing something, this is a more visceral and realistic portrayal of combat, treat it like a paintball game.
Yes, the game is short, the storyline isn't fleshed out well at all, and close combat involves little more than revving the chainsaw and hoping you get to the guy before he revs his chainsaw. But these aren't game breaking issues to me.