How is it? I was scared away by mixed reactions at launch and have been thinking about giving it a shot now though I'm still wary, but your opiniouns are trustworthy.
I remember playing SS 3 for the first time, and I was really annoyed by the beginning sections which felt like from different FPS. Here we don't have such problem, and the whole thing feels like a proper arcade shooter. But there is more story and characters involved. The NPC characters look really bad for a game published last year. When it comes to graphics, it feels more vibrant, closer to the original duology. I think it was a good move, plus the variety of locations and ambush spots is well done.
Some of the weapons now have secondary fire mods. For example laser gun has a powerful death ray, while the rocket launcher that loads up to five homing rockets that will lock onto enemies when fired. They are really useful in practice, especially in the later parts, where the number of enemies per encounter are way bigger. We also have new weapons, like for example autoshotgun - really powerful when it comes to close quarter fights. For the first time in the series, enemies can now take extra damage, when we shoot at their weak spot, such as their head. Weaker enemies can be dismembered by shooting at their arms or legs, which can incapacitate them. Overall the gameplay feels more smooth and better than in SS 3. Of course there are new monsters as well, some of them are included in my gallery. I won't be describing each one of them - they fit perfectly in the whole thing. At the beginning only annoying beast is Aurigan Haemovore - a vampire like creature who moves a lot. Add a dozen of them with normal monsters, and you can test, if your dodging and moving skills are good enough. So that's a big plus here as well.
We also have got side missions, but let's be frank - this is not a sandbox, and it takes only a little time for a detour to complete them. Also, they felt to me obligatory most of the time, due to introducing new weapons earlier on plus some usufel items to use for later in a big fights.
BUT
I don't like adding skill tree for Sam. It's really unnecessary, since dual wielding is the king here. We find through the game purple alien orbs that Sam crushes then inhales. There are overall 10 points to find, and it takes 5 Skill Points to unlock every dual-wielding ability. There are more of them to choose, but let's not kid ourselves - this feature is really not polished. Maybe the devs were too afraid to give double weapons from the start.
Also Croteam killed the fun of finding secrets. They made them really hard to find, and many times we don't even know, that they are at some parts of the levels. You know why? Because you have to do some jumping from point A to B, and than to C. And the jumping feels horrible in SS 4. The legion system which was advertised was for the most part a lie. Only the beginning and the huge battle before the boss shown glimpses of it.
The graphics look good (except the NPC characters, which I mentioned before), but I still had some problems, when it comes to the texture loading. Felt the same like some of the Unreal engine. Other than that, I haven't got any issues, performance drops, etc. I used the patched GOG version. Musically we have remixes and new tracks. Some of them really stand up, like town theme, while others are simply ok.
Overall I liked it. It felt like a proper SS game with gameplay and humor. Sam like to talk now, but his dialogue fits well with his character, and it was a good addition.
I didn't feel even for a moment that I was forcing myself through, and I'll be doing some replays later on.