Easy "Ouchies!" achievement...
	Various Steam Achievements...

Play under the Nightmare difficulty setting and run into enemies at every opportunity.

Complete the indicated task to unlock the achievement.

Achievement	How to unlock
I didn't even break a sweat	Be fully charged and have a power up and don't use either to defeat a boss.
I like explosions	Achieve 100,000 points on Nightmare.
I'm back	Defeat the same boss twice.
Its now my turn	Kill over 9000 enemies.
Ouchies!	Die a total of 100 times.
Speed runner	Get 100,000 points in under 100 seconds.
Time for an upgrade	Achieve 400,000 points.
pew pew	Defeat all the bosses.