I think its Dr. Jekyll and Mr. Hyde for the NES.
Since I'm pretty sure I'm right I'm gonna go ahead and post my game since I won't be back on till late tomorrow night. This is one of my favorite games ever.
I guess since there are no guesses yet I'll post another one. It was Keith Courage in Alpha Zones for the Turbografx. This next one should be pretty easy, even if you haven't played it.