When you have completed ALL the tournaments in the game this setting becomes an available option.

Both characters can be unlocked on any difficulty setting (you don't have to earn bullets to unlock them).

Unlock Nemo:
This English character who is a psycho is unlocked by completing ALL 8 tournaments.

Unlock Killen:
This Australian character who is a legend in 'The Club' is unlocked by completing the first 4 tournaments in the Ocean Liner Level.

Complete the tasks to get the corresponding Gamerscore.

Listmania - Gamerscore 5:
Save 5 Playlists in GunPlay.

Welcome To The Club - Gamerscore 10:
Win your first ranked match.

Taking Part That Counts - Gamerscore 10:
In a ranked team game be on the winning team.

Scavenger - Gamerscore 10:
In either Tournament mode or Single Event shoot ALL Skullshots on one level.

Scores On The Board - Gamerscore 10:
On any leaderboard get in the top 100,000.

Sharp Steel - Gamerscore 10:
On any difficulty level in Tournament mode complete the Steel Mill.

A Stately Achievement - Gamerscore 10:
On any difficulty level in Tournament mode complete Manor House.

Rack Em Up - Gamerscore 10:
In either Tournament mode or Single Event get your first x10 combo.

Crate Work - Gamerscore 10:
On any difficulty level in Tournament mode complete Warehouse.

Breakthrough - Gamerscore 10:
In either Tournament or Single Event smash 50 Doors.

Defcon 3 - Gamerscore 10:
On any difficulty level in Tournament mode complete Bunker.

Splash Down - Gamerscore 10:
On any difficulty level in Tournament mode complete Ocean Liner.

Waterway To Go - Gamerscore 10:
On any difficulty level in Tournament mode complete Venice.

Out On Probation - Gamerscore 10:
On any difficulty level in Tournament mode complete Prison.

Points Mean Prizes - Gamerscore 15:
Score 10,000 points in a Score Match.

Sprint The Gauntlet - Gamerscore 20:
Complete a Run the Gauntlet with 20 seconds left.

Target Man - Gamerscore 20:
In Team Skullshot shoot 100 Skull shot targets.

A Crate Effort - Gamerscore 20:
On Insane level complete Warehouse.

Big Game Hunted - Gamerscore 20:
In Hunter Hunted survive for 120 seconds as the hunted.

Save Our Souls - Gamerscore 20:
In either Tournament mode or Single Event spell the word SOS in the Warehouse.

Show Off - Gamerscore 20:
In either Tournament mode or Single Event get every ‘In Game Award’ in one level.

Siege Breaker - Gamerscore 20:
In Team Siege your team survives for more than 2 minutes.

Brawler - Gamerscore 20:
Get 100 Melee Kills in Ranked Matches.

Bunker Buster - Gamerscore 20:
On Insane level complete Bunker.

Watery Grave - Gamerscore 20:
On Insane level complete Ocean Liner.

Wet And Wild - Gamerscore 20:
On Insane level complete Venice.

Capture King - Gamerscore 20:
In Ranked Matches capture the base 25 times.

Full House - Gamerscore 20:
On Insane level complete Manor House.

One Shot - Gamerscore 20:
In Ranked matches get 100 Sniper Kills.

Hard Steel - Gamerscore 20:
On Insane level complete Steel Mill.

Hard Time - Gamerscore 20:
On Insane level complete Prison.

Premium Membership - Gamerscore 20:
Complete a Tournament on any difficulty with ALL 8 characters.

Demolition Man - Gamerscore 20:
In Ranked Matches get 100 Explosive Kills.

First Blood - Gamerscore 20:
In any Ranked Multiplayer game mode get 25 'First Kills'.

Fox Hunter - Gamerscore 20:
In Ranked Matches Kill the Enemy Fox 25 times.

Club On Tour - Gamerscore 25:
Win a ranked match in every location.

SkullMaster - Gamerscore 25:
Hit 5 Skullshots in a row (don't kill the bad guy in between).

Melee The Elephant - Gamerscore 25:
In either Tournament mode or Single Event Kill 30 enemies in a level with a melee attack.

Tabletopper - Gamerscore 25:
On any leaderboard in Tournament mode get in the top 5,000.

The Awards Show - Gamerscore 25:
In either Tournament mode or Single Event get one of every ‘In Game Award’.

Top Gun - Gamerscore 25:
In either Tournament mode or Single Event get more than 10,000 points for a single kill.

Warlord - Gamerscore 30:
In Tournament mode complete the game on any difficulty level.

Combo Killer - Gamerscore 30:
In either Tournament mode or Single Event reach the level objective with a maximum combo.

Efficiency - Gamerscore 30:
In either Tournament mode or Single Event kill every enemy on a level using less than 50 bullets.

Free For All Elite - Gamerscore 30:
Win any free-for-all game without dying.

Bag them Bones - Gamerscore 30:
In either Tournament or Single Event shoot ALL Skullshots on every level.

Hidden Treasures - Gamerscore 30:
In either Tournament mode or Single Event shoot ALL Secret Skullshots in every level.

Join The Club - Gamerscore 40:
In either Tournament mode or Single Event play an event with every one of the 6 unlocked characters.

No, Seriously - Gamerscore 40:
In Multiplayer Ranked Matches kill 10,001 people.

Skillzone - Gamerscore 40:
On Insane difficulty complete Warzone.