QUICKLY FINISH THE CRAWLERS
We are talking about the eighth mission of the story mode, where there is a section in which a horde of Crawlers will attack you, being one of the most complicated areas in the entire game.
Just before this section, you'll come to a room with lots of weapons... and a hammer. Ignore the weapons and grab the hammer, with which you can kill several Crawlers in one fell swoop. What's more, by hitting 3 or more creatures, you will unlock an achievement (in case you were wondering how to get the damn trophy and had no idea where to try).
UNLOCK THE KNIGHT HELMET
You just have to kill a Knight in any of the Spartan Ops that you will find in this game mode.
UNLOCK UNSC INFINITY SWEATSHIRT
You must get your Spartan to SR-5, after which the hoodie will automatically be unlocked for use as an avatar.
UNLOCK PLATINUM MARK VI
To achieve this, you will only have to beat the story mode on normal difficulty.
GET XP FAST
There are several hidden codes in the game that, if you decipher them, grant you additional XP points in varying amounts (between 1,000 and 50,000), as well as various rewards such as sketches. We leave you a video with the compilation of these codes so that you can enter them and get additional experience:
![Halo 4 | All Secret Codes [230,000+ XP, Armor, Emblems]](https://i.ytimg.com/vi/fjb_6PppG8s/0.jpg)
STEAL A WARTHOG
It is an armored vehicle and yes, it can be stolen. Be careful with the guards who will always guard it (if you use the plasma gun you will save yourself a lot of trouble, it is a very effective weapon in assaults of this type) and go to its upper part.
There is a hatch on the roof through which you can access the vehicle. Come in and enjoy it.
DISCOVER HIDDEN CHARACTERS
During the sixth chapter of the main campaign, you will find a couple of soldiers who will offer hilarious conversations in the lower part of the hangar. At first they will be silent, but then they will start talking and they are one of the best easter eggs in the game.
LAY DOWN THE WEAPONS
You must press at the same time: 
+ 
+ 
It will be deactivated as soon as you stop pressing the buttons.
Unlockables Legendary Campaign
By completing the campaign mode on Legendary difficulty we unlock 3 objects:
- Emblem 117
- Legendary Visor
- Mjolnir Mark VI Empowered Armor
Location of the 7 terminals
Throughout the entire campaign mode journey, there are 7 terminals that unlock the “Terminal” achievement", below we leave you a video so you can find them easily
Video with all Weapons, Armor, Skins, Kills, Skills and Specializations
All Halo 4 Achievements
Sunrise
Complete Mission 1 on any difficulty level.
Requiem
Complete Mission 2 on any difficulty level.
Forerunner
Complete Mission 3 on any difficulty level.
Infinity
Complete Mission 4 on any difficulty level.
Claimer
Complete Mission 5 on any difficulty level.
Closure
Complete Mission 6 on any difficulty level.
Composer
Complete mission 7 on any difficulty level.
Midnight
Complete mission 8 on any difficulty level.
Appropriate armor
Change your Spartan's armor on the Spartan armor card.
Badge
Change your emblem on the Spartan ID card.
Dominated
Change your Service Tag on your Spartan ID card.
What a smug!
Change your Spartan's pose on the Spartan ID card.
The legend of the lone wolf
Complete the Campaign solo on Legendary difficulty.
Dedicated to Crimson
Complete all chapters of the first 5 episodes of Spartan Ops, on any difficulty.
The legend of 117
Complete the Campaign on Legendary difficulty.
Contact the domain
Find a terminal in the Campaign.
Terminal
Find all 7 Campaign terminals.
I need a hero
Complete the Campaign on Heroic difficulty or higher
A legendary episode
Complete all chapters of Spartan Ops Episode 1 on Legendary difficulty.
Hermapocalypse
Complete any Campaign mission in co-op mode on Heroic difficulty or higher.
Hermageddon
Complete all Campaign missions in co-op mode on Heroic difficulty or higher.
Hard on deck combat
Win 20 War Games matches in Matchmaking.
Ascending
Reaches up to SR-20 range.
Wake up, John
Complete the Campaign on Normal difficulty or higher.
Dig into the past
Find and access the boss's service record in mission 1.
Midnight launch
In mission 2, you got a big jump with the Warthog at midnight.
Here my rifle, here my pistol
Carry a UNSC weapon throughout Mission 3 on Heroic difficulty or higher.
Brothers until the end
Complete Mission 4 without any avoidable Marine deaths on Heroic difficulty or higher.
Death
In Mission 5, steal a Wraith and destroy at least 4 Wraiths with it on Heroic difficulty or higher.
Explore the ground
In mission 6, trick or force a Hunter to fall into the void.
Dangerous adhesion
In Mission 7, in the Solo Campaign, take out both Hunters using only the sticky detonator.
Smash, Boss!
In Mission 8, kill 3 Crawlers with a single hit with the Grav Hammer.
Only Crimson
Complete a Spartan Ops chapter solo on Legendary difficulty.
Roses against violets
Find one of the RvB Easter Eggs in Spartan Ops.
no one has been left behind
Save at least one Marine in Chapter 3, Episode 2 of Spartan Ops on Heroic difficulty or higher.
white knight murder
Assassinate a knight in a Spartan Ops mission.
What blackout?
Complete Spartan Ops Chapter 4, Episode 5 without losing a generator on Heroic difficulty or higher.
There is no easy way out
In Chapter 1, Episode 5 of Spartan Ops, survive the enemy assault on defense, on Normal difficulty or higher.
The challenged
Complete a challenge.
The challenger
Complete 25 challenges.
skull
Complete any Campaign mission with 3 or more skulls on Heroic difficulty or higher.
I'm no longer a recruit
Reaches up to SR-5 rank.
Red vs Blue fan
Win 5 War Games matches in Matchmaking.
Operation completed
Complete a Spartan Ops mission on any difficulty level.
The cartographer
Create and save a custom map in Forge.
Change of game
Create and save a custom game type in War Games.
Snapshot!
Save a screenshot to Cinema.
Director
Save a video to Cinema.
Sharing is loving
Upload a file to your Shared Files.
Here you can find the Complete step-by-step guide to Halo 4.