This menu guide is written for Killer Instinct Classic 1 and 2 for Xbox, which you get when buying the Definitive Edition.

Please note: The menu guide is not 100% complete yet. This line will be removed when it's 100% complete.

The menus does not go in loop which makes them extremely easy to navigate. That means if you go to the top or to the bottom of the menus, nothing happens if you continue to press either the up or the down arrows.

Main menu:

PLAY
OPTIONS
LEADERBOARDS
ACHIEVEMENTS
EXTRAS
HELP

Play menu:

Play menu for Killer Instinct Classic 1.

FINAL VERSION
CLASSIC VERSION
ONLINE PLAY
TRAINING
If there are 5 options, then the first option is Resume game. If you then start a new game, the following prompt appears:
If you start a new game now, you will lose your
progress in your current game. Are you sure you want
to start a new game?
YES
NO

Play menu for Killer Instinct Classic 2:

Local play
Online play
Training.

If there are four options, the first option is Resume game, just like in Classic 1.

Online menu:

COMPETITIVE
CASUAL
PRIVATE

COMPETITIVE or CASUAL

When choosing any of those options, the following dialog comes up:
Quarter up! If you like, you can play a local game
while you wait for your opponent. You will be
notified when your match is ready.
CANCEL ONLINE PLAY REQUEST
PLAY WHILE I WAIT

Private

Opens up a window which is fully accessible with Narrator, where you can invite your friends to a match.

Options menu:

Options menu for Killer Instinct Classic 1:

CONTROL SETTINGS
GAME SETTINGS
DISPLAY SETTINGS
VOLUME CONTROLS
CHANGE PROFILE

Control settings

Please note: I'm not sure on how the controls can be adjusted. I don't see any ways of resetting to the default settings, so I'm afraid to mess up the controls if I mess too much around in this menu. If someone can help me to figure out how this works, it would be very much appreciated.

High attack for player 1
Low attack for player 1
High attack for player 2
Low attack for player 2

Game settings

Those are left and right sliders:
DIFFICULTY: Extra Easy, Easy, Medium, Hard and extra hard.
FINISHING MOVES: Off, on
ATTRACT MODE SOUNDS: Off, on
TEST MODE: off, on
MAX NETCODE DELAY: Numbers adjustment. Adjustment for delay while playing online.

Changing the difficulty level while you have a game in progress makes a loud boom, and then the following appears:
Changing this setting will restart the game. You will
lose your progress in the current game. Are you sure
you want to continue?
YES
NO

Display settings

BLOOD LEVEL
BLOOD COLOR
PARENTAL ADVISORY
SCREEN SIZE
BORDERART
SCALING EFFECTS

Volume controls

Those are slides which can be adjusted by pressing the left or right arrows.
GAME FIX
GAME MUSIC
MENU FIX
MENU MUSIC

Change profile

Opens up the login screen on the Xbox interface, where you can switch to an other profile/user. Works with Narrator.

Options menu for Killer Instinct Classic 2:

Game settings
display settings
border art
Volume control
change profile

LEADERBOARDS

Please note: I'm not sure on if that can become accessible at any point. If someone figures anything out, then I'll gladly hear about it.

Achievements

Opens up the achievements list, which is fully accessible with Narrator.

Extras

SPRITES
CUTSCENES
SCREENSHOTS
MUSIC
CREDITS

Please note: In those sub menus, the choices seems to be in multiple columns. You can only access things which you have unlocked.

Help

Believe it or not. To my big surprise and extreme excitement, this opens up a website, which seems to contain a fully accessible manual for the game. Use the Narrator mode to read when you can't use the d pad.

Pause menu:

RESUME
GO TO MENU
TAKE A SCREENSHOT
HELP