When you reach certain levels in Arcade mode weapons will become unlocked. Below is a list of the weapons that are unlocked and the level that must be reached.

Unlock XM-2119:
Reach Level 1

Unlock M4E:
Reach Level 2

Unlock P44M:
Reach Level 5

Unlock CAC82.
Reach Level 07

Unlock TM9V:
Reach Level 11

Unlock SAW24:
Reach Level 15

Unlock M45R:
Reach Level 19

Unlock SPR11:
Reach Level 23

Unlock PM6:
Reach Level 26

Unlock M94R:
Reach Level 30

Unlock AR4A:
Reach Level 32

Unlock Guardian II:
Reach Level 34

Unlock TR14:
Reach Level 38

Unlock P4512:
Reach Level 40


Unlock ABG1:
Reach Level 43

Unlock TK1B:
Reach Level 46

Unlock CPG7:
Reach Level 50

Unlock G50:
Reach Level 54

Unlock Guardian I:
Reach Level 60

Unlock M209:
Reach Level 61

Unlock SPR3:
Reach Level 69

Unlock MP10:
Reach Level 77

Unlock SR308:
Reach Level 85

Unlock SG112:
Reach Level 93

Unlock XMW21:
Reach Level 99

In Single-Player mode the first two costumes are automatically available but to unlock the others you have to reach the indicated level. These levels along with the costume they unlock are listed below.

Unlock Desert Camo:
Reach level 7.

Unlock Policeman:
Reach level 10.

Unlock Tough Guy:
Reach level 15.

Unlock Sky Camo:
Reach level 18.

Unlock World War II Uniform:
Reach level 20.

Unlock Cowboy:
Reach level 23.

Unlock Urban Camo:
Reach level 30.

Unlock Virtua Cop:
Reach level 34.

Unlock Future Warrior:
Reach level 38.

Unlock Ninja:
Reach level 50.

Unlock Panda Suit:
Reach level 60.

Unlock Gold Uniform:
Reach level 99.

When you manage to complete the following modes the indicated Party mode will become an available option.

Unlock Ninja Mode:
Clear Arcade Mode once.

Unlock Paradise Mode:
Clear Ninja Mode once.