The Good: Fantastic combat and gameplay, the slicing engine is fun, graphics are amazing, great soundtrack
The Bad: Extremely short, generic tone throughout, confusing story, enemies repeat often, nothing to do outside of combat
The Metal Gear franchise hasn't seen too many spin-offs. Acid being the last one. Revengeance puts you in the shoes of Raiden, a cyborg fighting against other cyborgs for the greater good. The plot is supposed to hover around MGS4, but it's boiled down to a confusing, and ultimately, uninteresting mess. There's something going on about children's brains being harvested for implants and people making money off of war. Raiden is the good guy trying to stop all this, but the game is so short and broken up so much that it's hard to follow.
What is great is all the action. Raiden responds wonderfully and has an array of flashy moves that would put most action adventure games to shame. As you progress through the game you can upgrade your life, fuel cells, weapons, and moves. The whole game pretty much revolves around a slicing engine. When you defeat an enemy enough you can slow down time and use the right analog stick to slice enemies up into ribbons. It's pretty fun and never really gets old, but it's sensitive and some times finicky. Boss fights will rely on this and lining up squares can cost you the entire battle if you aren't quick enough.
I honestly wish Platinum never put stealth sections in the game. This isn't Solid Snake, I want to run around slicing things up. The enemy placement isn't smart and laid out like a typical Metal Gear game. You get seen most of the time even if you try hard not to. One problem lies in the fact that there's not much else to do. It's just wave after wave of enemies and then a boss fight. It also doesn't help that the game is ridiculously hard outside of easy mode. Even though it took me less than 6.5 hours to finish the game, it was broken up throughout a year of playing. I would spend hours on some areas just because of how hard the game can be. There's no block button. Let me throw that out there right now. Instead you can dodge and parry which is extremely difficult to get down right. You can die in just a few hits and healing relies on slicing enemies at the right moment and getting there nano strands to fully heal. You must slice them before they hit the ground, this can be really tricky to master.
The enemies also repeat often and the game is overly generic in tone. Sure the graphics are fantastic, the music is great, and the action is fast paced and looks amazing. However, the enemies are just generic soldiers and Geckos. The environments nearly all look the same and some boss fights even repeat. I appreciate the difficulty which forces you to master the combat system, but a larger variety of gamplay would have been nice.
So the final question is this: Is Revengeance the be all-end all of the action adventure genre? Not likely. Sure it's up there with some of the better games combat wise, but everything else just falls a bit flat.