First of all, what do you mean by contact graphics, powerup acquisition, and save game effects?
Contact graphics - you a bullet hits the enemy/the player hits the enemy
Powerup acquisition - what happens when you grab a powerup or something (does it just play a sound, or does a message pop up, or something else)
Save game effects - graphical fanfare that comes up when you save the game
I use Timeline FX ( http://www.rigzsoft.co.uk/ )for most of my effects. Either as whole animated sprites or single frames to use in the particle object in C2.
That does look useful, though I'm making a 16bit platformer. HD explosion may seem a bit out of place...