Done a little more playing. I'm actually not as far along as I thought. I'm still in Chapter 2 actually but the game continues to be interesting as I experiment with a few things.
Combat is a little more generous than my first impression. The MULES are subject to the same balance mechanics as you are so dealing with them is actually easier than I was lead on, despite them having weapons. They unfortunately can take a beating, much like trying to beat up guards in MGS1/2, but they stay down a bit longer when you knock them out. Sneaking into one of their encampments was actually really fun, and I may hit up the first one I discovered earlier to see if I can find more stolen goods. For those wondering what I mean about balance mechanics, it's easy to knock them off balance by switching directions or even colliding with them when they do catch up which lets them stay open for a beating from you. Granted, they can do the same as you, but leading them into bad terrain can give you as much of an advantage as them. Likewise, the game takes momentum seriously, so running down a hill with a full cargo load and colliding with one of them will knock them flat on their asses as well. It's actually really clever so far, though it may change once I start to get into the bigger open areas.
I feel the easiest way to really explain the core game mechanics is that it takes some elements most people take for granted in other titles and adds a few layers of realism to it to actually make them more challenging. It's too easy in this game to get greedy and overload Sam with too much weight which causes several problems, but due to some of the online mechanics, its not as simple as just dropping needless materials because anything you leave out in the open can eventually be picked up by other players if you abandon it for too long. The environments are more realistic with rocky terrain and high winds causing issues usually ignored in most action titles with explorations options. Oddly enough, it's the Timefall rain that is the biggest hazard so far for me. It degrades the cargo you carry the longer you walk around in it. It only gets worse because that's usually when B.T.s show up. They will force you to choose between either taking it very slow to get past them unmolested while your cargo degrades quickly by staying in the Timefall, or you can risk hoofing it and watch as they all attack you, potentially make you drop and damage all your cargo, and usually involve trying to escape a giant cthulu oil whale that transforms the whole region into an oil ocean. So there is some interesting mechanics that makes this a bit more unusual than just go here and there. I actually overloaded Sam's load last night cause I kept finding and picking up too many lost cargo packages, I discovered the fatigue mechanic which slows down Sam's ability to regenerate stamina and slowly degrades its maximum as well. I also destroyed two pairs of shoes doing this which was nice in some ways because it sowed that shoes actually have a long shelf life if you don't overdue it.
The biggest mechanic that is often downplayed is the games online mechanics which are trying to build a stronger community of people. I just gained the ability to create bridges, and since unlocking it, I've noticed a few more player generated ones have been popping up. Likewise you can leave lost cargo in special terminals the players create for other players to obtain and deliver for you instead. You can also share unused weapons and items for other players to take as well. There is a big push for player cooperation in this game that is reminiscent of the Souls series.
I just unlocked my first vehicle, but I'm holding off until I do the big run back to the main Bridges base. I also unlocked minor delivery quests, so I'm dealing with those at the moment before jumping back into the main plot.