Find a Chaos Crystal (this games version of red barrels) in any of the levels, once you've found it don't just run up and destroy it. You need to allow the enemies to deal damage to you until you only have a sliver of health left, the Chaos Crystals do surprisingly little damage to you. Then destroy it, taking you with it.
This one can be a bit glitchy, since you basically have to be hugging the crystal.