SPOILERS FOR A GREAT GAME!
I loved my time with DUSK. Amazing game. Recommend if you're a classic shooter fan. I also recommend following their advice with "Pick the middle difficulty for a first time playthrough." As someone who's not quite a vet but has experience, I found that it was difficult enough to keep tension, but also not so hard I had to replay tense parts.
As someone who is studying encounter design in FPS games right now, I loved the weapon arsenal, as well as the masterful control of tension and release, and the everchanging encounter design.
If you're familiar, feel free to skip my thoughts on the weapons to see some examples of how they work well to create interesting solutions to encounters.
Sickles/Sword - First weapon! They are surprisingly good at killing quickly, with damage comparable to the pistol and a high fire rate. With the obvious downside of being a melee weapon in an FPS. In the final episode it gets upgraded to a sword, with a charge attack and damage to keep it a valid option in close range scenarios. But, after E1M2, I was just using my Super Shotgun for this. REALLY IMPORTANT if you're sickle starting every level though!
The Pistol(s) - Serves as an early game weaker weapon. Doom (2016) starts you off with a weaker pistol, and once you have ammo and a decent arsenal, you never go back. It feels awkward to have a useless weapon like that alongside a more beefy arsenal. DUSK keeps it relevant by allowing it to be wielded akimbo. I was using it to clear the military grunts and other chaff all the way to the second to last level.
Shotgun(s) - Similar to the pistols, but I use the pistols to clear a crowd, I use the shotguns to chunk down a target at medium range, or clear out one enemy at a time. They are relevant in the middle of Episode 1 because they can be dual wielded, but stay relevant after the Super Shotgun because they have a tighter spread! You can actually kill things at a medium range with a shotgun in a video game?!
Super Shotgun - My beloved. Staple late game. When I see a tight turn ahead of me, I clutch this thing like a toddler clutches a teddy bear. I like how it clears chaff enemies well, but doesn't one-hit later game enemies; Red Mages take 2 shots, Wendigos take 3. The tradeoff for such power is the spread, but sometimes you use this to hit a cluster of enemies in close combat. Up there with the greats.
Assault Rifle - Workhorse of the arsenal. Good for any situation. Almost don't like that except it chews through ammo and has the whole "Jack of all Trades, master of none, better than a master of one" thing going on. Like, in any situation, there's probably a specific weapon that excels at it better, but it's good at it and I like it.
Hunting Rifle - Love it dearly. Reminiscent of the Half-Life revolver. Low ammo and reloads slowly, but it packs as much punch as a close range Super Shotgun at any range. Flamethrower killer, Red Mage counter, the nature of the thing encourages tactical thinking and target prioritization. Good gun.
Crossbow - Lacks some of the feedback of the others, but excels in its role. Something Dusk does that strays from the pack is it lacks a BFG equivalent. Personally I think this fits the role; the piercing makes it great at clearing out thick crowds, and you have the Mortar and Riveter for clusters. I find it pairs well with the "definitely not Super Hot" syringe, as you line up a shot and take them all out. But this gets so convoluted, sometimes I just use this like the Assault Rifle.
Mortar - THIS is the bread and butter of the arsenal. Used it like dynamite in Blood. Think something's around a corner? Bounce it around and check. See a swarm of enemies? Lob it in. The fact that you can hold up to 50 of these? The same amount as shotgun shells? Grenades take enough thought (player splash damage, bouncing off surfaces, aiming for the middle of the pack) that them being a bit strong and plentiful doesn't break the game. And it just feels nice.
Riveter - Rocket launcher, that you can spam. Treat ammo for it like caviar. Whereas the Mortar takes time and is a careful thing, this is your panic button. Whenever I see a Cowgirl? I spam this until I see a fine red mist. The occasional rocket jump to a secret is very fun.
Dusk likes to pick an "enemy palette" for a level, and build encounters based on a 2 enemy dynamic facilitated by the environment. (Here I am talking about the traditional mid-level encounters, rather than arena combat).
The level starts off with a combination of Mages and Leathernecks (Melee, chainsaw units) in tight spaces and gradually increasing darkness. Later on, it introduces Wendigos, in a way that enforces the main environmental elements and fears of Darkness and Claustrophobia.
To introduce the enemies in this new context, it alternates them. The first mage starts in the end of a hallway, shooting at you as soon as you see them, tutorializing desired combat behavior. This says, "You have a disadvantage in narrow, long spaces against this enemy" and how to mitigate this disadvantage. Or, in simpler terms, "Hey, Mages are dangerous in hallways, so shoot then duck out."
As the room opens up, there is a Leatherneck and a supporting Mage. If the player keeps their distance in the hallway, they get the spacial advantage of putting distance between them and a chainsaw to the face. If they rush in, they learn that Leathernecks have the advantage in an open but tight space. This is the opposite of the other enemy, and is intentionally juxtaposed against it.
Leatherneck and supporting Mage (over Leatherneck's right shoulder) in bright spacial condition.
The player has been reminded/introduced to where enemies have a spacial advantage, so now we can add variation through lighting. Mages have a glowing effect around them, so they are visible in the dark. This both serves as balance, so the player isn't shot completely off guard, and as a guidance tool. In this second segment of the encounter, this glowing effect is used to lure the player into an ambush and guide them towards progress.
"Enemies lead me to progress" is a reliable heuristic for experienced gamers, so this glowing mage says "Forwards is in the dark behind me." A player who is not wary of the dark might rush down the dark corridor, and a more cautious one might slowly walk through. The wary player is rewarded by hearing the Leatherneck in advance, where as the unwary player is caught off-guard in the dark. This helps develop the player heuristic of "Enemies hide in the dark." This is intentionally towards the back of a corridor, so the player is tested on their understanding of enemy spacial disadvantage.
After this encounter, the level designer needs to be careful. Having all of these challenges creates the unspoken promise that "I overcame this, and I will be rewarded for this." And, to get the player into this encounter, the level designer used the heuristic of "Progress is where the enemies are." So, they reward the player with knowledge about progress, by guiding them to the Yellow Door. Good lock and key design introduces a door first, then they get the key, and here it is done in a way that feels organic. "I wasn't railroaded here, in this maze of tunnels I just so happened to find the way forwards after this fight!"