If you've finished the game and are itching for more, there's an entire map section you may have missed, that felt to me like it was initially planned as a DLC by EA and then Respawn probably pushed EA to just include it.
*Thumbs up*

While you're here, I'll also point out a few more sections to revisit that are shorter, but worthwhile. When you put all of them together, it's several hours of play, with lore, buffs, skins, challenging encounters and new environments along the way.

-->This guide is for Non-Completionists who missed some areas during the game!

Completionists will have done these sections before finishing the game, so if you're a completionist and have finished the game, this guide is not for you, you can just stop reading it and move on with your browsing.

This guide is to help people go back directly to interesting areas they may have missed. (A lot of people finish the game without doing these sections, but they don't have the patience or time to spend hours roaming around trying to find out if there's anything they missed.)

So this one's for you non-completionists! :)

To be clear for the trigger-happy flamers out there: No it's not an actual DLC, yes it's already included in the game, but yes that 1st area is DLC-like in my opinion (your opinion may differ and that's fine, that's not the point of the guide). I found it was like is often done with actual DLC's in games such as Tomb Raider, Batman etc.: an area that is decently long, includes new lore, and some interesting fights. And EA with their track record certainly could have tried to sell this off as a DLC (and would have gotten rightfully criticized for it).

The thing is, contrary to a DLC that you'd buy and they'd show you where to start it, this area is already in the game you paid for, yet there's a good chance you didn't play it! That's why I took the time to write this up, to help people find content they paid for but missed, and prolong their enjoyment of the game.

So there you go, I believe I've painfully accurately described what this guide is about. If you don't agree with that definition that's fine, it just means this guide's not for you. Some people definitely find it useful.

Very Minor Spoiler Alert: This guide points to areas that are readily accessible but easy to miss during the main storyline. If you'd rather find them yourself without any hint (especially if you're reading this and haven't finished the game yet), then I suggest you stop reading and come back once you've done everything you wanted to.

Go back to Zeffo, and head for the Crash Site section of the map. Then, go up the very large reactor structure in the middle of the map, and keep going up all the way to the top, instead of going left like you did following the story the first time through. You'll need to double-jump to get there, which is why you "miss it" the first time. (if you need to neutralize some flying robots as you head up, you're going the right way).

You'll be able to enter the reactor, into the Venator Wreckage map. This is a fairly large map which felt to me comparable to small DLC's you can buy in games like Tomb Raider, Batman etc, but might have have been just included in the main game because it wasn't big enough to sell, or maybe because EA wanted to try out a clean single-player release without cash grabs.

Anyway it has a storyline in the form of lore you'll find with audio snippets, multiple good fights, secrets, special environmental elements not found anywhere else, plus it has some useful rewards and extra skins.

I hope you enjoy!

After you've done the above: while you're in that Zeffo/Crash Site area, there's more to look for, if you haven't done it already (possibly because you didn't find it or because it was too hard):

There's the Broken Wing map section nearby, in which you'll need to get past a serious Boss then move on to a small section with a puzzle etc. This one is reached by going up one level above the big nasty guy you see on your left when you reach the Crash Site map (not the one in the arena, the other one).

Also if you care for Chests, there are many to be found in Crash Site which you won't have found the first time around.

As mentioned completionists will have done it already, but I'm putting this up for the people who may have moved on along the storyline.

It's good content that's well worth going back to!

Hope you enjoy, let me know!

The following are shorter than the Zeffo areas mentioned above, but are well worth making sure you've completed as well since we're on the topic.

Head to Dathomir. As you leave the Mantis, go left. Go up the ramp (now accessible if you hadn't noticed, makes a nice shortcut!). Head toward the Tomb as you've done a few times by now. Once you've jumped across the multiple gaps to get to the tomb, I would recommend going indoors and using the save point, and backtrack to head outside. Now as you're exiting walking down the stairs outside, in front of you are the multiple jumps you would take to head back to the ship. Don't. Head left instead. You should see a darker-colored path, which heads toward a section with 2 facing walls you have to wallrun across.
And there you go, enjoy... and reap the rewards!

Head to Bogano.
Area 1: (Revisiting this reveals new stuff)
Go back to Hermit's Abode. You'll find a few surprises there.

Area 2: (Interesting goodies previously inaccessible-I recommend doing this before the last planet in the game actually)
Explore the Abandoned Workshop, top to bottom, left right and center. A rewarding venture you'll find.

Please rate Thumbs up if you found it useful or appreciate the time I spent writing this for you! Or write a positive comment. It'll tell me it was worth doing...and it'll compensate for some people taking free stabs at it just because it's not useful for them, or because they assume things without actually reading the guide or playing the area(s). and btw apologies for the long "disclaimer" section at the top, it seems for some people it's necessary.

Cheers!