Find ancient armor (Single Player only)

Destroy 6 disruptors without taking a hit on level 4 (Single Player only)

Destroy all the disruptors with the shotgun on level 4 (Single Player only)

Kill 3 enemies using the laser on level 8 (Single Player only)

Don't let the VIP lose any HP on level 10 (Single Player only)

Finish level 12 without getting hit by a tower (Single Player only)

Exhaust 6 nests

Have an enemy die from a grenade after you died

Kill 15 enemies without losing any HP on a single level

Kill 150 enemies

Interrupt 10 flying enemy attacks with a shotgun

Stand on every planet in the game

Complete 6 levels in a row without dying

Catch 5 healing bloobs

Kill 17 enemies from a different planet

Collect a gold medal on each level

Finish a level (other than level 01) destroying only the marked enemies (Single Player only)

Kill 4 enemies with a single shot from the stun gun

Kill 8 enemies with a single shot from the rocket launcher

Finish all the levels on hard difficulty