I have compiled a set of plugins, vsts and other useful tools for use creating soundscapes, sound effects, and music for the game jam!
TWEAKBENCH: Plenty of vst instruments and sound manipulators here. Wide variety of different sounds and effects.
Piano One: A great piano with a few reverb and delay effects built in.
Earthbound Soundfont Pack: Huge soundpack with plenty of synths, basses, leads, and percussion from Earthbound. Great if you want to make a retro sounding track!
LazySnake: Electric piano with a rhodes sound.
Feel free to add your own tools to the list!