Finished the early access campaign. I have to say I didn't expect this game to turn out so good, holy shit.
The start is boring IMO and the first three levels definitely need redoing in some way. IIRC especially the third one is guilty of constant imps on ledges. But after that it's nonstop balls to the wall action.
What I said about it during the alpha still applies, and perhaps even x10 - this is an actual, honest to God shooter, with no unnecessary bullshit added on top. The guns are slick. The movement is fast. The enemies may be derivative but they all serve their purposes and work well (probably because they are so derivative, don't change the winning formula etc) - I also like the later "supercharged" ones. It's a good way of extending the bestiary with stronger monsters with very little costs involved.
I like the guns quite a bit. They are almost all useful, and so are their alt-fires, and they pack roight propa punch. The only ones that I don't like much are the nade launcher (the physics on the bounce are TERRIBLE) and the chaingun (I hardly ever use it instead of the dual smgs, and once you get the plasma gun it becomes more or less obsolete). The alt-fire on the plasma gun is also pretty worthless, but the basic fire mode is gud, so eh. Also, it can't be stressed enough how important it is that switching between guns is so fast - you switch between them often since different weapons are fit for different purposes, and the fact that it's near-instant is very gud. MANY shooters don't seem to understand this.
I played on very hard, and the game sure as hell provides good challenge in the later levels. There were many times when I was running around with 25 hp desperately looking for medkits while assholes would continue to spawn all around.
Level design is ok. I think it's nothing to write home about, but at the same time, it's important that it avoids all the aggravating shit like constant arenas, gimmicks and monster closets. They are still sorta railroady, but often they are open enough or you get to choose between picking path_A or path_B first, so you don't mind much. The secrets can be clever though, and I managed to miss a bunch, including some that I knew were there but I couldn't figure out how to open. The monster spawns are also used well (read: in a non-aggravating manner), which is a plus, because usually spawns tend to annoy me.
That said, there is the one obvious stinker, which is no penalty for dying. I said the game provides good challenge, but that's only if you adopt some self-imposed rules, like trying to beat them on one life. I did that, only continuing from checkpoints if I died very close to the end and couldn't bother restarting, and really, sometimes it was very hard. But respawning for free just defeats the purpose of... anything. They absolutely need to add save states, even if only for the checkpoints - obviously I'd be more happy with quick saving, but the levels are short enough that ultimately I wouldn't mind checkpoints only, but the point still stands that they need to do something to punish dying.
Still, all in all I had YUGE fun with this. Most fun I've had with a shooter in the last 5 years for sure, with the only exception being Overload. It also puts shit like Ion Maiden completely to shame.