I'm a big fan of FEAR for laying the groundwork for a new type of Pacman-type FPS gameplay that the industry never expounded upon, so when I see something calling itself FEAR-inspired I get all giddy. And having played the demo, it already shows a ton of promise on top of potentially being mechanically stronger than FEAR.
The first thing Trepang teaches you is that stealth is a thing, kind of. It doesn't overshadow the action like in Crysis. Instead stealth is a means to reposition yourself safely, or survey the situation without being expected to memorize enemy spawn locations. So no going around crouchwalking behind every enemy and pressing the takedown button (you could do it, but why would you). The cloak ability is immensely useful, and doesn't last that long to be abuseable. You can shoot out lights to make it easier to sneak around, but enemies can still detect you if you're crouching in darkness, it just takes a bit longer. Moreover shooting out lights makes noise and each arena tends to have a dozen lights, so most of the time you'll rather be using your cloak. For arenas with a lot of light sources I wish there was a central power breaker you could shoot to disable all lights in the room to save you the tedium of shooting everything.
One thing I very much like is the game's health system, which is a mix of Halo and nuDoom and the best of both worlds. It's split between health and armor, where armor is refilled by killing enemies and walking over the armor they dropped, where health can only be restored by medkits that are placed in the level between every two or so fights. Every enemy dropping armor means you want to move forwards and camp less if you want to live longer, but you still have to worry about health in the long-term in case you overextend. By not allowing the player carry medkits like in FEAR, medkits (and full armor pick-ups) in Trepang become a more effective means of luring the player towards the action rather than camping at the edges of the arena. It is also more preferable than having to press the medkit button every 5 seconds in a fight to not die, having to wait for your shield to recharge behind cover, or having to press F and watch a epic cinematic takedown before you can control your character again.
Also interesting is the hostage mechanic. If you sneak up on an enemy from behind, or if you smack them first or knock them to the ground, you can grab and use them as a meatshield. One thing this encourages is starting a fight by grabbing someone from behind and being able to tank some extra hits. Another is that the enemies you fight are somewhat compassionate and won't fire at one of their comrades (if you didn't shoot already), instead opting to circle around you for a safe line of sight. But within this brief ceasefire you're also given a brief moment to scan the room or reposition yourself. However, having a meatshield cripples your mobility and reduces your shotgun rate of fire, so there's some drawbacks to consider to prevent you from obsessively finding a new meatshield ASAP. You can kill a grabbed enemy by snapping their neck, though I wish you could fire your gun while doing so to keep the gameplay running smooth. Otherwise you can throw grabbed enemies into others to knock them down, but unfortunately the throwing distance and power is too weak for this option to be any useful.
In terms of movement, you can vault over objects to make jumping through office windows less cumbersome than in FEAR, but you also have a ridiculously powerful slide that automatically ragdolls any enemy it hits. It's fast, it covers a lot of distance, and doesn't cost all that much stamina, and quite frankly it is broken. No enemy can really stand up to the slide (aside from the single boss enemy at the end of the demo). I love its role, but there needs to be a bigger drawback to using it (consuming your entire stamina bar, for one). Unfortunately sliding also has a tendency to get you stuck on level geometry because you can't even slightly turn when sliding, which is why I hope in the future you can at least turn left and right somewhat when sliding. Another problem is that the enemies are knocked away with such force that it's easy to lose track of them:
Besides that, there's also for some reason an UT-style double-tap dash, whose purpose I can't comprehend. It barely covers any distance and the double-tap input introduces a lot of inherent input lag to the action, meaning it's not a very attractive option. Maybe it throws off the enemy aim a little? I sure couldn't tell. In any case it would be more preferable if it was an one-tap dash (because double-tap inputs in general suck and it's too easy to accidentally do one). Alternatively, the dash and slide could switch roles where the dash instead shoulder rams enemies, which solves the problem of them leaving your FOV, and makes it a bit more balanced since a dash has a short duration as opposed to the long-ass slide which keeps knocking everything over in its path. Instead the slide would be used to drastically reduce the chances of getting hit while rushing forwards while not actually knocking over enemies like bowling pins. If you want to conserve button inputs, slides could be executed by double-tapping a one-tap dash button. In this case the double-tap input wouldn't be as much of a problem since with the first tap and ensuing dash you're already gaining speed, which is already what you set out to do by wanting to slide. Sort of like a double jump.
You've also got your melee attacks, though unlike in FEAR they are not one-hit kills. I can live with this, as a standard melee attack is supposed to stun an enemy so you can grab them from the front and use them as a meatshield. Being able to just walk up to enemies already firing at you and grab them would be kind of broken on its own. On top of that you have jump attacks which deal more damage and ragdoll enemies, but they're also not really worth using. If I want to ragdoll them, I'd use the slide. If I want to kill them, I'd use my shotgun instead. And if I want a meatshield I'd use the regular melee attack. For these reasons I think that jump attacks should be instant-kills to make them at least somewhat worth using, given that you're already making yourself extra vulnerable by setting up a running jump.
Because it's FEAR-inspired, it's gotta have slo-mo (called Focus here), and thankfully it takes the less broken approach of Focus only refilling on kills like in Max Payne 1. However, I'm personally not fond of slo-mo mechanics in general. You press one button and you're given a massive combat advantage with almost no drawbacks, unlike something like the shootdodge in Max Payne where you get a brief burst of mobility and slo-mo but are left vulnerable after you hit the ground. Focus can let you shoot grenades mid-air, but gameplay-wise it's a very shallow mechanic. It only makes things easier. Especially with the amount of Focus you're given, you can breeze through almost entire encounters with it. Hence why people complained that FEAR was too easy and just a matter of 'just activate slo-mo and kill everything while moving forwards lol'. It might be true that the odds are so stacked against you that using Focus is essential, but the main problem is that the game briefly turns into Easy Mode while Focus is active. At the very least your maximum Focus duration should be much shorter so you can't rely on it like a crutch, but a better alternative would be to have another gameplay option that also consumes Focus but with some more depth to it. Like how in Vanquish your slo-mo energy is shared with your knee thrusters and melee attacks. One idea here could be a brief wallhack that consumes all your Focus, but alerts all enemies to your position when used.
There's a big problem with the weapon arsenal right now in that they're all freaking inaccurate and too weak at the mid-range, at which point the shotgun becomes the most viable choice. That's not the worst thing, the shotgun has some fine kinaesthetics, but it becomes a problem in larger more open arenas with sparser cover. Quite frankly I don't get this need for weapon bloom, every other mechanic already encourages close/medium range combat. Making the weapon accuracy so poor to force you to close the distance on top of that is somewhat redundant. Max Payne just paints a single dot on your screen where the bullets will go to 95% of the time, placing the emphasis on scoring headshots instead, which is a whole lot more preferable than having to crouch and GO SLOW in order to have your weapon be remotely accurate, or to rely on your Focus which gives you much better accuracy on all weapons.
A larger underlying problem is the weapon variety, in that it's falling into the same trappings that most military shooters and FEAR partially did by making most weapons just generic assault rifles but with slightly different stats. So I've got my SMG and AR and silenced AR which all essentially do the same thing. Since I already have a cloak and I am already playing bowling ball with enemies, realism isn't that much of a sticking factor here, at which point I might as well have some more futuristic out-there guns like the power weapons in FEAR. Another thing I don't like is the two-weapon limit. Since I don't foresee Trepang having an unique approach to damage types like Halo's weapon sandbox, three weapons is the absolute minimum required to allow for some interesting weapon combination. 95% of the time in games with two-weapon limits you pick the generic assault rifle that's decent at all ranges (or in this case the shotgun since the accuracy for everything is already on par with it) because that's what enemies drop ammo for all the time, and a limited-ammo power weapon like a sniper rifle/rocket launcher which is always handed to you by the level, since the fight ahead is often designed around you using this weapon, which undermines the idea of giving the player more choice. By being able to carry three, I could either carry two more specialized weapons on top of the all-rounder weapon (like in Bulletstorm), or take enough specialized weapons with me that taking a generic assault rifle isn't necessary.
Visual clarity is also a big issue I found, especially with how dark some rooms are and how blinding many lights are. In the darkness you can barely see an enemy even if they have a flashlight pointing at you. Flares and other bright light sources tend to have this obnoxious effect where they draw a horizontal line across your entire screen, which is overkill and makes me think of tripwire mine lasers instead. The commandos with red night vision goggles stand out better, though their goggles will keep burning even if they're dead, so it's easy to confuse a knocked-down commando with a dead one. Actually, on the whole it's hard to distinguish between dead and knocked-down enemies (especially when sliding around). One other part of the reason is that the enemies don't stand out much from the background color-wise, you've got beige camos against white-ish walls. Something more blue/green-ish would stand out more against the background. Furthermore, the visual effects for signifying whether you are covered in darkness or not are rather confusing, and could be rather simply replaced by something akin to Thief's Light Gem for increased clarity, like the HUD icon for whether you are making any noise.
The fact that your flashlight beam is always emitted from the barrel of your current weapon is rather obnoxious, since actions such as reloading or sprinting won't make the flashlight actually point where you're looking at. For this reason it would be infinitely more preferable to have the flashlight be mounted to your helmet like in FEAR, so it always illuminates anything in front of you regardless of what you're doing with your gun. That, and increasing the circumference of the flashlight beam to FEAR's level so that in dark areas it doesn't just illuminate a small center portion of your screen.
To sum it up, the game definitely has potential. Hopefully it manages to expand on the weapon/enemy/level variety, since that was a major stickler with FEAR.