-Overall Gameplay
First of all, every single gameplay aspect from 2016 has been significantly improved. The game plays faster, better, more intense, forces you to think faster and multitask. You can comfortably ignore every single negative review that's under 3 hours of play time, those people didn't put effort into learning the game or even listening to what the developers have been saying since the first gameplay demo.

DOOM Eternal is a power fantasy, but you won't be given that power fantasy for free, you will have to earn it. The game has a particular gameplay loop that the developers refer to as "The Fun Zone", to which they claim if you do a specific set of activities, you are guaranteed to have fun with the game. They are correct. You juggle between glory killing demons for health, burning them with the Flame Belch for armor, and Chainsawing them for ammo. You also have the ability to dash twice in quick succession, which gives incredible mobility options. Due to those options, the enemies have also been made faster, therefore you are forced to keep moving even more than in 2016. It's been balanced in such a way that if you actively choose to ignore these things, you will not have a fun time.


-Combat
Some of those balance changes include: regular melee attack deals next to no damage, this makes it so you can't simply cheese your way through fodder for free health, this is an FPS after all. Ammo cap is in much lower quantities than in 2016, this is so that you're forced to use the Chainsaw as well as given the incentive to switch weapons, and do not worry, one Chainsaw pip is recharged over time for free, and fodder spawns in the combat arenas until you complete them, so you can never get stuck without ammo.

Every gun has received balance changes to better fit the gameplay loop, here is a pro tip on how to use each:

The lower tier guns (Combat Shotgun, Heavy Cannon and Plasma Rifle) all got buffs to remain viable for the entire game:
~The Sticky Bomb is incredible crowd control for Fodder Demons.
~Precision Bolt is a hitscan weapon that snipes weak points as well as give you faster weapon switching, coordinating weapon combos with it between each repetition is crucial to increasing your DPS.
~The Microwave Beam can freeze any non-boss enemy in the game.

The high tier guns (Rocket Launcher, Super Shotgun, Ballista and Chaingun) all fulfill different purposes as well as combo incredibly well with the Precision Bolt in successive repetitions.
~The Rocket Launcher PB combo is the highest DPS in the game, best used at mid range, the Lock On mod can quickly delete a good portion of Heavy Demons.
~The Ballista PB combo has the best range due to both of those being hitscan weapons, the Destroyer Blade mod is a mini BFG when mastered properly, use bhops, jump pads, grenades and ice bombs to help mitigate the movement penalty.
~The Super Shotgun PB combo is the best close range combo, SSG-PB-SSG deletes every Heavy Demon with less health than a Pain Elemental or a Cyber Mancubus, the Meathook adds yet another layer to the game's already impressive mobility options, specifically giving you the ability to yeet across entire arenas and help you stay in the air, making dodging easier, it also allows you to skip certain jumping puzzles entirely with the help of somewhat lucky enemy placement.
~The Chaingun by itself is rarely to be used unless you aren't comfortable with your weapon switching, however the Energy Shield is the most overpowered mod in the game, it makes you immune to all damage aside from damage coming from the ground surface, excellent for escaping sticky situations, as well as when you dash into enemies with the shield active, it falters them.


-Level Design
Every single level has its own visual style and unique layout, all of them do different things that make use of the added mobility. They all look absolutely stunning and are breathtaking to explore. Secrets tend to be laid out in such a way where you can see them easily, but can't immediately see how to get to them which makes hunting for them very enjoyable, I never got frustrated trying to acquire any secret in the game. The combat arenas are all designed with mobility in mind, with added monkey bars and whatnot, you feel rewarded for always being on the move. All in all a stark contrast to the rather monotonous look of 2016, no more Mars corridors, the game keeps itself looking fresh throughout.


-Music
It's Mick Gordon, except he's better than ever.


-Story
If you don't care about it, you're free to skip the cutscenes, even the developers said so, so don't make claims that the game is forcing the story upon you.

BUT.

If you enjoyed the lore in 2016, you will be blown away, it's expanded and the puzzle pieces are all falling into place.

The plot itself is very simplistic, but the storytelling is absolutely masterful.

DOOM Eternal really understands that it is, in fact, a videogame and takes full advantage of it, the storytelling works precisely because of the fact. It wouldn't work as a movie or tv show and I think that's where many people criticize it, they're looking at it as if it were presented as a movie, when it isn't. On the other hand, the people who claim it makes no sense didn't read the lore from 2016 or the lore from this game itself, the answers are all there, it simply won't handhold you to dump exposition onto the player when Doom Guy already knows the full context of what's going on, doing so would break the pace of the game and story.

This game is a genuine showcase of videogame storytelling done right. Few games executed their stories as good as this one. This isn't a game that tries to be a movie, and that's exactly why it works. More games should utilize their own medium to tell their stories more effectively.


-Battlemode
Not the reason I bought the game, but I really enjoy playing it, the Spicy Demons discord server can help you if you want to get good at it. Would definitely recommend playing this mode with a friend, it's much more fun that way.


-Performance
This is a 2020 game that runs better than almost all AAA games from the past 5 years, id Software are optimization wizards, stable 144 fps on 1440p max settings with a 1080Ti, speechless.


-Miscellaneous
Easter eggs. DOOM Eternal is absolutely filled with them and they all put a gigantic smile on my face.


-Nitpicks
A couple of bugs are said to be fixed by the time DLC 2 releases, they include; Blood Punch randomly not registering on direct hit, Chansaw randomly failing to target a nearby enemy, the Marauder not faltering on sloped surfaces.


-Conclusion
DOOM Eternal promises many things, and fulfills every single one of them. This is a video game that knows what it is and executes that perfectly. An incredibly fun sequel that manages to connect the entire franchise together, id outdid themselves with this one.

10/10