Broderbund's Prince of Persia is generally regarded as a revolutionary game. The idea isn't entirely without merit - the game did, essentially, create a genre that combined 2D side-scrolling action with puzzle solving. However, everything it ever did, Blizzard's (yes, the RTS king's) Blackthorne does far better.
Think of it as Prince of Persia with tons more style. Blizzard, after all, always infused its games with a great deal of style. You're the prince of a race of people enslaved by evil demon pig goblin bastards. You've infiltrated the slave mines, and you're going to make your way through enemy territory to finally kill the head evil demon pig goblin bastard. You're pissed off, you're dark and shaggy, you're wearing blue jeans and a Hanes Beefy T. (In essence, a typical grunge musician.) And you have a shotgun. That's just unbelievably cool.
Despite your being armed (with an unlimited supply of ammo, it seems), most of the game will be spent hiding from bad guys in the shadows, picking just the right moments when to take pot shots at them. If you try to make like Rambo, you will be quickly killed (and the bad guys will make fun of you while you're lying dead). Once you kill the bad guys, you loot their corpses for stuff like bombs. Most of the puzzles consist of finding keys and knowing when to use your limited supply of bombs (and what kinds of bombs to use where). It's actually very simple, once you've figured out the obvious differences between the three kinds of bombs, but the puzzles can still get very difficult and require a great deal of thinking, without ever getting too frustrating to make you quit. And while you're hunting for keys and bombs, you'll learn to take it slow and hide at every corner, as bad guys can literally pop out of the ceiling if you step on a pressure plate. As you're doing that, you can partake fully of the graphics and sound, which aren't spectacular but mostly contribute very well to the murky, shadowy mood of the game.
Blackthorne's finely tuned balance of action, puzzles, and style make it the great game it is. 2D action-puzzlers were never much of a genre, but Blackthorne is their undisputed king.