Vice - Project Doom (NES / Famicom)

While Bayou Billy may get the most attention for combining a bunch of different genres in a single game on the NES, there were other titles that also did this.  One of my favorite of the bunch was Vice: Project Doom where you played some mysterious guy fighting a mysterious enemy.  The game had driving, shooting, and side-scrolling action.  Stick that in your pipe and smoke it, Konami.

The Adventures of Bayou Billy (NES / Famicom)

Sometimes I wonder how I even managed to play some of the games of my youth.  When I was a kid, I played the hell out of Bayou Billy, and even managed to finish the game.  However, coming back to the game as an adult I realize that it's actually really tough.  Even the first level is handing my backside to me on a regular basis.  It's games like these that really show me how challenging games on the upper end of the difficulty scale can be.