No cheats, just farming at the Free Roam stage.
Here's a tip on how to rip through the stages:
Use the species that starts with the "Claw" zooid, and make a wall of claws. Charge at your enemies, attack with the Claws and watch as everything just dies. The "Jet" movement zooid of that species really helps with maneuverability as well.
I call this build: The Wall of Death.
Here's an example of what you should aim for.