So, tools:
FlashPunk, FlashDevelop, Graphics Gale, LMMS, Bfxr, Wavosaur, mp3loop, Gimp(?), DAME or Ogmo 2.
And maybe some code pieces from these libs\files:
Advanced Platform Engine for FlashPunk, FlashPunk skeleton, as3corelib, cjke-punk.transition, nl.stroep.chain. Oh, and my previous LD entry, I guess.