I didn't like this as much as I thought I would. I find the premise of it absolutely fascinating, but the execution lacking. 

It's weird.. I've never finished a book and thought that it was simultaneously about so much and nothing at all. I think what's bothering me is that the book didn't really have any sort of resolution. There was no goal the characters were striving towards. They were just going from one place to another, killing people/creatures of other races. This plus the author's way of skipping over so much made me wonder what I even got out of the book. The first half is essentially one long prologue and even then so much is glossed over, so the book feels slow and fast at the same time.

I'm also confused about the message this book is trying to convey. For a while, I felt like the author was making commentary on the ruthlessness of humans and the nonchalant use of the military instead of attempting peaceful means at first, but then that kind of fell apart. Then he kept mentioning other races who thought humans made a good meal, farming humans for meat, which of course disgusted the MC, so I thought maybe he's trying to make a point here, to show the hypocrisy, but nothing came of that either. So at the end, I was left with nothing. I'm disappointed that there was barely anything about how fucked up it was what they were doing. Yeah, the MC has one moment where he feels terrible, but then he's fine again because someone he cared about got killed.

The MC leaves a lot to be desired as well. He's a prime example of a Gary Stu and once you realise that, you can't even pretend that he's also in constant danger and might die at any moment, so there's not even that tension.

I did enjoy the friendships of the Old Farts, the brief discussions on aging, marriage, getting a second chance, but from characterisation to the attempts at humour, this book feels like something written with one thought in mind: "What would a dude like to read?"