Metal gear solid type gameplay, and also a top down shooter with classy graphics.

But for real, this game has different sorts of pros and cons and it's not going to be for everyone.

Story wise, it's ok, I had suspicions at the start of the game after the 3rd level or so about what was going to happen, but kept playing none the less. Turns out they were true, and I don't know how to feel about that. Let's just say, that yes, sometimes things are too good to be true.

Mechanics..oh man..you'll find tons of people complaining about the mechanics, and I could do that too, but if you want to start playing the game without any spoilers, be it story, weapons, tactics and etc related, then just play the game. If you are however unsure if you have wasted money on the game and want to redeem it, here's some things that might put you off if you're looking for a good stealth genre game:

-Enemy AI is incredibly wack, I mean, WACK. You're either not gonna get spotted for punching someone's teammate, or the whole room will instantly know where you are, rush you, and obliterate you with shotgun spam.
-Stealth will NOT be a theme for the entirety of the game. There are going to be times where you will slip up. If you wanna finish the missions and not have to be like me and torture yourself trying to be the stealthiest maniac around, then just grab a decent weapon that you like and go on a rampage.
-Level design: Jesus. ♥♥♥♥♥♥♥. Christ. Ever wanted to feel like a rat in a maze? No? Well me too, but this game decided we had to. Navigating the maps is maddening, and you'll need a extra 20 minutes or so to explore around and see what it's like. I suggest opening the maps in the Map Editor and resizing them and looking around, if that is an option that is available of course, i'm not sure if you could do that before you finish the main campaign at least once.
-Weapons: Some are silent, most are loud, and by some I mean 2 or 3. The most incredibly weapon that you can have at your disposal will be your trusty knife, and the MK23. That knife has saved me so much time and ammo, and the silenced pistol is perfect to dispose of one or two enemies and run out of a window.

In short: Intravenous features a satisfying but at times mildly annoying gameplay, humor that only a mother could love, a decent amount of maps, a built-in Map Editor and Workshop for the Steam Community, Achievements, a Custom Difficulty Option, and a average playtime to finish the campaign of about 4-8 hours (atleast for me my first playthrough was 4 hours, went to 8 after replaying to test some things out).