Buy something from a vending machine.

Get your first blaster.

Throw a grenade.

Destroy 5 Sewer Turrets.

Collect 30 Junk.

Find the Robo-Claw.

Destroy 4 yellow doors in the Sewers.

Grab 20 objects with the Grab N' Blast.

Defeat the Sewer Boss.

Destroy 10 Robo Spiders.

Destroy 10 Mini Bots.