Finished it on Hard II or whatever it was called. Game was rather easy apart from some early run-ins with hordes guarding NERO loot while armed with just a pistol and before you get some useful perks (or more focus). Cash and supplies was never a problem, I think I went low on it only once after buying a bunch of bike upgrades at Cope's camp after hitting trust level 2 or something.
I'm not sure if I liked this or Mad Max more as far as generic open world game design goes. At least the combat was better than Mad Max's batman awesome button system (which got really boring really fast) and the stealth was ok even if it was yet another instance of "cloaking field tall grass and crouching makes you less loud" stealth, so clearing camps wasn't really boring unlike strongholds in Mad Max. But Mad Max had better vehicular gameplay (although not as much of it as it fucking should have had). Also it took longer than in Mad Max to max out all the upgrades IIRC, but similar to Mad Max it's almost impossible not to get all the good perks by the half way-ish point of the game.
I liked riding 'muh bike across the pretty Oregon wilderness, it has some of that same appeal horse riding RDR's wilderness had (especially in RDR2), but I started abusing fast travel sometime after I got to Lost Lake. Fuel scavenging was nice while it mattered, by which I mean by the point I realized that NERO checkpoints respawn fuel cans and had the region maps surveyed and some other locations for fuel memorized.
Horde killing was fun, but it's a shame that apart from (very late) story missions and 2 or 3 NERO loot points it lacks a reason to bother with it, apart from maybe trust grinding. That and it pissed me off to no end that you can't see shit from outside the cave and can't determine how close you are to the freaks inside the cave while crouching until they start charging at you (although maybe that one perk helps with this, but shootan perks are too good to skip for it).
Had a few fun "emergent" random things happen like a breaker smacking parts of a horde, a reacher chasing a deer like Wile E Coyote, various cougar mauling freaks or cougars running away from them encounters, a horde clearing a raider camp for me because their gunfire lured it to them.
I think this game was too long for its own good, as for me it became kind of monotonous after a point with nothing over the horizon (gameplay mechanics-wise) to look forwards to (RDR2 had the same damn problem, but that one was just a fucking chore to finish due to the fucking stockholm syndrome story making you stick with the retarded gang and no challenge after the first 1/3 of the game), and I didn't like the tunnels/narrow passes connecting the 3 first regions as it made the map feel cramped. Also it really could have used or done something original, it feels like there is nothing in this game that you already have not seen before, with maybe the exception of hordes.
The protagonist's VA felt too angsty or whatever you can call his attitude problem that made his talking a bit annoying. Although I guess the PTSD implications kind of explain it. I liked the biker theme, there should be more sandboxy games going for that stereotypical depiction of an outlaw MC, getting into races, beating people up with motorcycle chains or brass knuckles, customizing your bike, riding the long roads etc.