Just a truly phenomenal game. In my opinion, it builds off Doom 2016 nicely. To keep things short, the gameplay is similar to D16's but with added features (flamethrowers, meat hook, ice bomb ect.) making it even better. There is still that fast paced gameplay but now with more movement systems. The levels may seem odd to some, feeling a bit unnatural, but it's like this because it's supposed to imitate the original level design. Other aspects of the game may also seem odd, like the camera changes, in today's eyes but they're also there to imitate the games of the past. More demons have unique weaknesses which makes the game more fun and engaging. No weapon/weapon mod is truly a jack of all trades and each one has its purpose. The bosses and mini-bosses are challenging and often times not too frustrating to play against. I often times found myself in a trance when in combat which comes to prove how engaging the game is. Oh and the music! The music is quite strong and feels at home with Doom once again. Imo, the Doom 2016 soundtrack felt a little better but Doom Eternal's soundtrack is still strong nonetheless.
The graphics, level detail, and skyboxes are really good too. The graphics look pretty good by today's standards and so does the details to the levels. The skyboxes are honestly such a treat in some levels to the point where I found myself interested and immersed in my surroundings.
My only complaints is that I found trying to collect all the secrets a bit of a chore and it broke away from the gameplay. The story is rather confusing on its own and you can understand it with the codex but reading all these entries to understand the story seems boring and lazy. I see many people complaining about changes with the UI, HUD, gameplay, levels, platforming and the controversial anti-cheat on pc (that is now removed) which is fair but I don't have a problem with any of these really.
If money/time is not an issue, please buy this game. This game is such a treat and is worth every penny.