Shoot down 20 flying planes.
Buy all of the weapons.
Destroy 5 of the big track quatro pounder tanks
Use 20 Invincibility power ups on yourself.
Use 30 Shields to protect yourself.
Achieve an "Outstanding" kill combo 100 times.
Use 50 Medipacks to heal yourself.
Blow up 5000 wooden crates.
Blow up 1500 red barrels.
Upgrade any weapon, killstreak or item to the max.
Upgrade any weapon for the first time.
Complete the Boot Camp tutorial mission.
Reach the rank of General of the Army.
Reach 10000 kills in total.
Reach the rank of General of the Army for a second time.