Attain 5 stars on all SP levels
Complete the Final Stage in Story Mode
Complete Marathon Mode
Reach Wave 10 in Survivor Mode
Complete your first level
Reach a combo of 99 kills in any mode
Finish a stage without taking any damage
Kill 10 enemies with one sledgehammer power-up
Finish a stage without killing a single enemy
Finish a stage without ever changing lanes
Get 20 projectile kills in a single stage
Reach Stage 2-5 in Marathon Mode
Finish a stage with the crosshair off