Great work...the progress so far looks great, this might just turn out to be the game fans have been waiting for since Jazz Jackrabbit 2. While I haven't done any 3D modelling (trying to learn Blender right now tho), and have somewhat limited programming experience, I can give you a few suggestions:


Weapons:

a few basic melee weapons (to fall back on should ammo run scarce, or for those people who prefer melee combat),character specific of course, each with specials (activated when "sugar rush" meter is at least half full)

Jazz
Turtle Chopper - your basic sword with a carrot hilt, not very powerful during normal attack, but compensates by posessing greater than average speed and the ability to deflect incoming projectiles.
SPECIAL - Jazz jumps high into the air, coming crashing down (destroying any airborne enemies in the process, and creating a restricted shockwave upon hitting the ground, significantly damaging enemies in the blast radius, and stunning enemies just outside - there should be a small recovery time after the attack. [Powered Up - blast radius is slightly larger, and recovery is shortened]

Spaz
Squirrel-chucks - Spaz, being the nut that he is prefers to wield these crude nunchaku of unwilling squirrels. Weaker than Jazz's sword, but much faster..
SPECIAL - Rabid Squirrels, Spaz spins in circle, squirrels are enraged and rabid and will bite into enemies causing more damage, with the chance of turning the affected enemy against the others for a short time


*yawn* - actually, it's getting kind of late, so I think I will post more ideas later. Keep up the good work.