The easiest modern day parallels to Blackthorne would be titles like Serious Sam or Evil Dead. They feature a testosterone-driven masculine protagonist who is set in an alien infested world and given plenty of weapons to start wreaking havoc. Most of the time, this situation is amusing and funny. Blackthorne certainly was in its time and that's why it's re-released for the Game Boy Advance today.
Blackthorne's main character is Kyle Blackthorne, a military man who is pit against a cast full of mutated monsters and Tolkien-like goblins that are armed not with bows and arrows but explosives and guns. Blackthorne himself is armed with a shotgun. The bad guys are headed by the sinister Sarlac. The rest of the story actually gets a bit confusing and unlike the semi-logical ones that can be found in the Starcraft or Warcraft lore, it's clear that Blizzard wasn't as sharp on the storytelling as they are now. Unlike traditional platform titles, though, there is a hidden z-axis in the game. While you can shoot projectiles from one side of the screen to the other, Blackthorne is able to hide in the shadows; an action that will cause projectiles to miss him when invoked. The cunning monsters themselves can also hide in the shadows, making for some good old western style shootouts when it plays correctly.
Remarkably, the action isn't really the high point of the game.
Blackthorne's toughest moments will come when you have to leap across chasms, climb up obstacles and generally get to the other side of the screen without falling to an untimely demise. There are no guides or suggestions available. This generally means you'll have to practice some trial and error. The hero is equipped with some niceties like a running jump and the ability to dangle off ledges. Think about all the moves Lara Croft was able to do but in a 2D setting.
Back then one of the more innovative features in the game is the inclusion of allied characters. They provide a focal point for all the storytelling. The conversations also break up the monotony of running back and forth activating bridges or finding keys. However, in this day and age, it no longer seems very innovative.
Blackthorne's oft-imitated tough guy versus the world motif has literally been done to death on console gaming machines. So when the soundtrack doesn't shine and sound effects are no better than the original Sound Blaster ones I heard on the PC, you become less forgiving. I certainly was - it would've been better if the sounds were re-sampled. The graphics, particularly the main characters, could have used a makeover.
Ultimately, there is about a day's worth of gameplay in Blackthorne, and even on a Sunday, a good player could finish and still probably fit in church, lunch, dinner and maybe even football. It plays at a slower pace than recent action games. It wants to give you the impression it's a thinking person's game, but the repetitive level design doesn't allow it to sell itself properly. However solid the core game is, after you finish, there's not much to do other than replay the whole thing - going through the same motions again. That part bugs me the most. Compared to the Lost Vikings and Rock'n'Roll racing, Blackthorne has lost a bit of its edge and unfortunately, there's no additional development effort put into this release to spruce it back up.