This is proper old school thrash / death metal. There are many great riffs here. This is the main rhythm guitar, we'll look at the solos and fills separately as usual.
The high difficulty rating is more down to the speed / precision picking at certain places. However, if you work at those fast sections they should come together quite quickly. So don't be put off by that, but if you are a beginner leave the hard parts until later.
Just go at it slow and keep it tight, then build speed. This type of playing is quite easy once you get the hang of it, even played fast. That's because it is nearly all easy powerchords with your fretboard hand and consistent palm muting on just two strings with your strumming hand.
Generally, use downstrokes for the picking during the slower parts, and when it hits the throttle switch to alternate picking (down / upstrokes). This is a typical thrash style of playing. Downstrokes are easier to play, and have a little more chunkiness. Whereas alternate strokes give you speed.
Intro - There are a few chunky riffs here as the guitar and drums set the pace. It's quite a long intro, but quite easy to play. The trick to all these types of songs is to get the picking consistent and in time...
Go as slow as you need, but keep the timing consistent. Once you can 'forget' your picking hand then work at getting your fretboard hand to move fast between chord changes without missing a beat. Once you get that consistent too, start going faster.
Verse - Catchy riffs, and not too hard as long as you apply the above principles in your practice. This part is a lot of fun to play and great for developing your skills!
Pre-Chorus - Still sticking to just downstrokes, but now slide between powerchords.
Chorus - Time to alternate pick and speed up. Practice in the same way as before, and build speed as you can. With practice you'll crack it.
Fill 1 backing - Just play and hold powerchords while the lead does its thing.
Fill 2 backing - This comes in after another verse, and is probably one of the simplest, yet fun parts to play in the whole song!
Chorus 2 - Starts similar to the first pre-chorus riff except faster, with alternate picking. Like all the riffs, they are actually quite short, but repeat a lot.
Solo Backing - Be thankful you are not the lead guitarist while playing this.
Bridge / Verses - Another series of riffs, all full speed ahead.
Ending - By now your guitar strings may have melted.