I would like to see more enemies that shot at you if you were close enough. In Jazz 2 the only enemy that did that which I can think of was a monkey. Give Lizards, turtles, and the 'Demon Scourge'(What I call anything the somewhat resembles Bilsy and Bolly) guns or fire attacks or something.
Oh, and enemy concept: The Demon Scourge, which is an army commanded by Bilsy and Bubba and the soilders in someway resemble them. Two examples I can think of are the demons from Jazz 2 and the floating demon... things from HH94. I think the demonish things in Deserto could qaulify.
I dunno I'm thinking waaay to 12-year oldish on ideas right now.

Edit-Changed a name