Kill 5000 enemies.
Kill 4750 enemies.
Kill 4500 enemies.
Kill 4250 enemies.
Kill 4000 enemies.
Kill 3750 enemies.
Collect 125 upgrades.
Kill 3500 enemies.
Kill 3250 enemies.
Kill 3000 enemies.
Kill 2750 enemies.
Kill 2500 enemies.
Beat stage 3.
Score more than 50,000 points in a single run.
Beat stage 2.
Collect 50 upgrades.
Kill 1000 enemies.
Beat stage 1.
Kill 100 enemies.
Collect 5 upgrades.
Beat stage 4.
Beat stage 5.