I played this a little bit. I've not seen anything really bad to justify the overwhelmingly negative user reviews yet. It's definitely lacking technically, I have to lock this to 30fps and maybe later on I will also have to reduce settings if the frame rate is reduced to a crawl when shit hits the fan (say when some Wanzer is chasing you and wreaking havoc all around you). If it was running at a silky smooth 60fps like MGSV easily did I'd be fine with its graphics and think it's pretty great overall but at such a reduced framerate it's passable. Either way it's not a problem unless performance does drop further later on.
Mechanically it's something like a cross between Splinter Cell (Blacklist I guess) and pre-V Metal Gear Solid games. Like, this could be on PSP like Peace Walker since it also limits your movements. You can't go prone for example, only duck with the common waist height cover objects and such. At the same time it has very much a reliance on crafting gadgets (maybe like MG Survive? I never tried that) you will need to use if you hope to make it through a fight.
There's no instant-win stealth kill, it took me a full 3-hit combo with a crowbar I found laying around to take someone unaware down from behind and another strike to finish him off. I don't know how it would go if I tried to use the standard melee attack you can do while holding a gun. With that in mind enemies will inevitably be alerted if you try to take more than one on if there's no full-stealth way around in that particular path or whatever. And since they have so much better gear you better use all your crafted items, from tripmines to RC explosives, Molotovs and all sorts of other things.
There's also no radar or mark enemies to see them through walls or whatever, so far they're only marked if in-camera and close enough and there's a crafted gadget that you throw and it reveals enemies nearby but it also doesn't last forever. You'd have seen that in some of the trailers for sure. There's also a vague directional warning shown when they're near or closing in, I'm not exactly sure of the limits, maybe it's a bit like the MGS: Portable Ops sound based radar?
So all that makes it fundamentally different to other games like MGS and even Splinter Cell which some may have expected it to be a clone of (that's what I thought too, maybe I'd have even preferred it as such) which is why some of them trash it so hard with barely any play time. Plus the game kinda throws you off the deep end, I just reached a point (see it in the first screenshot) where I'll definitely have to utilize gadgets and early weapons I found to proceed as I can't find a way around the enemies and I'm only a few minutes in the game with it still popping tutorials up as I find a new object or element. And it's not like I have a ton of stuff to craft said items with at this point, I'll probably run out of stuff if I use them in dumb ways while trying to figure it all out.
I also died once already by alerting enemies in a very disadvantageous position earlier on when the game was tunneling me in a different area but I wanted to grab some items I saw near the enemies, ha. During that I also found the first pistol you start with takes several shots to down the enemies, they seem fully armored up on top of having the firepower and numbers against you. I actually ran out of ammo while trying to fend them off at that point, took a few down, then had to take the ammo they dropped but the last dude got me anyway as I ran out again and couldn't get close enough for melee using the available cover (almost did it with a final daring leap off some boxes in front of him but he got me mid air haha).
I can't say if it's worthwhile for sure of course, maybe some of the negative reviews with actual play time are right to trash it as the content, mission design, encounter design, fiddly mechanics for the necessary gadgets or whatever else, could be pretty bad all things considered but with what I have seen so far I think the game has good ideas, decent implementations of them outside the actual performance of the game and seems pretty nicely done so far.
I'd guess for now it's most wise to simply wait and see what's gonna be the consensus from people giving it a real chance once the dust settles down.
As for people trashing the game as an insult to the series just because it's not a "real Front Mission" when it doesn't even pretend to be since it doesn't have the Front Mission name maybe they should get educated on that the very second ever Front Mission entry was the damn cool
Front Mission:
Gun Hazard.