This guide is to help who is starting on the high difficulty of the game, but all players can found interesting things here.

English is not my core language (I'm learning), so, if you find an error, report to me =)

The default keys for weapons is the numbers 1 at 9. On the flow of gameplay, you are needed to use every weapon, and change each other faster than you can.
To do it, you need to re-bind the keys of weapons.

In my case, I use a common keyboard and a mouse with two extra buttons, my bind setup is:

I use the default bindings for movement, adding the mouse scroll up to jump. It takes more simple to do a b-hop.
You can bind the jump key on scroll using this console command (' to open console):

I use the default bindings here, just adding mouse three to Equipment Laucher.

I change de bind for weapons based on my comfort, be free to change for your own.
Some note, I'm using the SSG on Q, Ballista on Mouse 4, and Rocket Laucher on Mouse 5 because is the weapons I most use, is faster to me change each they using this binding.

This can be changed while my gameplay is evolving.

The weapons combo is the core of Doom mechanics. Is essential to learn about them and practice the fast switch weapon. Here are some combos with help in your playthrough.
A good place to training fast weapon switching is on the boss of Sentinel Prime, he just dies with execution, so, you be free to shoot on him a lot.

SSG + Ballista
This combo (and most others), consist of a shoot with SuperShotgun and switching to Ballista faster as you can and shoot, repeating the process.
It is good for enemies close to you.

PrecisionBolt + Ballista
This combo is a little harder than others, you need to aim with PB, shoot, and switch to Ballista.
It is good for enemies far from you.

This is the formula of the combos, basically is:
shoot with a weapon > switch to other and shoot > repeat/switch to another weapon
Example, Rocket Launcher + Ballista:

Use your imagination to create new combos! 🦄

The movement mechanics involve a lot of things. In a text, it can be really hard to explain. So, I found a really good video explaining all these things.

Special credits to the Hell of Deimos (follow this guy, he's really awesome)

https://www.youtube.com/watch?v=vzV-udCUJkg
https://www.youtube.com/watch?v=GOtjhyjKslY

Test the scroll mouse to jump, it's more simple to get the Momentum timing. High FPS helps a lot!

Doom Eternal has a lot of peoples doing Speed Run. Watch these guys playing is awesome and you can be learning a lot about the game.
I'm putting here some streamers I watch frequently. All recommendations are welcome.

• Jamesplaysamumu[www.twitch.tv]
  
• Xiae[www.twitch.tv]
  
• Xamide[www.twitch.tv]
  
• Protehqc[www.twitch.tv]
  
• Raitro[www.twitch.tv]
  
• UmbraPenumbra_[www.twitch.tv]
  
• DeadshotDemps[www.twitch.tv]

You can consult the World Records on the official site SpeedRun - Doom Eternal[www.speedrun.com]

Thank you for reading, if you enjoy the content, review the guide and add to your favorites!
If you have some tricks ou questions, put a comentary, I respond soon as possible.