Helldivers is pretty cool I think. I'll have more thoughts when I spend more time in it, but here are my thoughts so far:
It feels good as far as the gunplay and overall mission-board go. I think there's some new player clunkiness I need to get over, mainly with using the stratagems, but I can easily see how player skill can improve your effectiveness and your ability to contribute to the fight.
I have seen more than a few clips of people pulling off awesome movement tricks, and I'm excited to get more into that. The shooting mechanics feel good, even if I miss the automatic reloads the FPS games I used to play had. That being said, how accuracy is handled feels a lot more natural.
The TTK (for the first mission anyway) felt pretty good. It felt powerful but not instant-kill. I assume at later difficulties, it will be longer without lacking the punch I'm feeling now. If it's just bigger swarms, that might turn me off a little bit.
The multiplayer seems to be handled well enough, but it's pretty obvious they need some server-side help; the day I bought the game I sat in a loading queue for almost 2 hours before giving up. I feel like they could have coded the tutorial and your personal ship as a client-side service rather than needing to be directly connected to matchmaking servers. However, the matchmaking/grouping feels wonderfully fluid when it works.
If you want an idea for the philosophy behind the game, watch the 1997 Starship Troopers with the reminder that the writer and director basically made this movie a big fat middle finger of a parody about Robert A. Heinlein, one of the most authoritarian-apologist/worshipper to have ever written a book that wasn't directly fellating any of the contemporary dictators we might know by name (e.g Mao, Stalin, Nixon, etc.) (seriously read Stranger in a Strange Land the difference between the first and second parts of the book are fucking jarring.)
With that in mind, I'm gonna crush some fucking bugs and scrap some bots for spare parts for a couple weeks!