Is it just me, or does Red Faction: Armageddon look like a new Doom game? I saw it and immediately thought of it.

I bought the 5$ Deus Ex + Invisible war package off of Steam (10 year anniversary and all, big sale) and played an hour and a half of Deus Ex and I can't help but notice how loose the entire thing feels. The shooting and fighting is surprisingly tight for its time, but the core mechanics of how the story progresses are not well-defined enough; I've twice found myself bypassing entire sections of the game by simply exploring the wrong area too soon and bungling them up because of a lack of equipment that is received by accomplishing earlier bits of the game.  
 
The fact that you can simply waltz into a later part of a level and have the game actually act like you're in it instead of giving you some sort of notification that you missed something is very frustrating. Is this what "open-ended" meant in 2000? Missions can be broken if you explore the wrong place at the wrong time? I really don't get it. 
 
That said, I can immediately see why some people love this game: I'm definitely growing fond of it. Even though it's often boxy, ugly and too open and I spend a lot of time just walking around without accomplishing anything, many areas definitely have "character". The story isn't half-bad, either. Whether it's the best game ever made remains to be determined, but I have overall positive impressions of it, despite navigational troubles that a simple minimap or objective marker would fix.