Having played through 1 within the last week or so, I think it held up surprisingly well, even though in recent years I have criticized the game quite a lot. I still think the pacing is all kinds of shit since too often it just keeps throwing waves & waves of enemies against you in a single location, but if you use all the tools available to you, it can be pretty fun a TPS even on Crushing. Just so long as you don't totally suck, there are some tricks to playing it that make its difficulty mostly a non-issue.
Some tricks/tips that I find helpful for crushing in Uncharted 1 and most even generally for the games in the Uncharted franchise:
-sometimes it's far better to NOT stick to a cover but just using large walls/obstacles in the environment as cover while still standing & moving freely. Sticking out from cover to aim & shoot leaves you far more vulnerable in a lot of situations, whereas standing & moving freely while aiming & being behind large cover can give you just as much cover while giving you better aim since you can move slowly into the view of the enemy while already aiming at the exact right direction (or even get a shot at enemies outside their view) instead of the more jarring pop-up from sticky cover that can throw your aim way off and needs more correcting adjustments just to get your aim at the general direction of the enemy.
-learn to take advantage of the Steel Fist; in some situations (so long as it's not a shotgun dude that has the time to one-and-done shoot & kill you) it can be beneficial to just rush towards an enemy to get a couple of run 'n' gun shots in and then one-hit-KOing an enemy than trying to stay put behind some cover and aiming & shooting the enemy, especially if it's only one enemy in that direction while others are flanking you from the other side
-git gud enough to land headshots with at least some kind of decent-ish accuracy. It saves you a lot of ammo so you don't need to do death-defying ammo-gathering rounds. Enemies are bullet sponges only if you don't hit them in the head, for most enemies 1 hit is enough (did Uncharted 1 have enemies with helmets that need 2 hits? I already forgot
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-pistol is GOAT general weapon in Uncharted 1, their accuracy is high & they kill with a single headshot like any other weapon and they have a lot of ammo, so you can stay in one spot if there is a good spot, get kills pretty efficiently and aren't immediately in the danger of running out of ammo. I often cleared waves of enemies with just a pistol (& maybe a shot or two from a shotgun). Pistol is a bit less useful in Uncharted 2 in some situations since it adds some heavily armored enemies that pistols are kind useless against
-I usually try to hold one weapon that has a lot of ammo and one that is super strong but only has relatively few ammo. My favorite combo is some regular pistol + shotgun, but something like Wes + AK-47 is also something I used.. Pistol for long(er)-distance gun fighting that might need a bullet or two, shotgun for close-up gun fighting & cover-blind-fire OHKs when some enemies are stupid enough to try to rush you & come close enough. Having a shotgun and Desert 5 can be a deadly combo, but at times you'll easily run out of ammo and that's not always a good thing.
-blind-fire is great with ALL weapons, though most useful with a shotgun. I wouldn't necessarily waste Wes-bullets to it, but with weapons that have lots of ammo, often blind-fire is a perfectly fine alternative to get rid of enemies that are getting too close (blind-fire actually works on enemies surprisingly far away, they don't necessarily have to be breathing down your neck for it to work). It wastes bullets, but it keeps you safe from enemy fire. It's especially good when you are near-death and enemies are coming up close. Instead of having to risk it and popping up to aim, just shoot while still staying behind cover. Sometimes it might be useful even if you spend your last bullets to it, if it gives you a few seconds more time to heal yourself and then go running for more ammo.
-my general rule of thumb is to be a bit conservative with the use of grenades in most situations (they are get-out-of-jail-free-card levels of useful when all else seems to fail), usually only go crazy with them in larger environments where there WILL be several waves of enemies from all directions by one point or the other or if there's just an irresistible group of enemies all lumped together. Grenades can be really useful in those kinds of situations. It's just a waste in some situations unless your grenades are full and there are ones laying around.
-let the enemies who have tendency to rush you do just that and when they are close enough, get a shotgun-blindfire-kill. Don't risk your life when there are 8 enemies all shooting at you. It's better to first get rid of the enemies that don't stay away by waiting them to. Though of course there are situations where getting rid of enemies as quickly as possible is the best solution. Then you should not let tons of enemies get too close.
-unless they prevent you from staying in some good spot, let laser-snipers be for a while. They are often the least dangerous enemies since they take such a (relatively) long time to get their aim on you & shoot.
-try to find a place that limits the amount of directions enemies can flank you from. It doesn't necessarily have to be anything too special, but a place where enemies can get to you from all sides is, of course, not a very good one. There are places where this isn't possible or it can be hard to figure out on your own where the best place is when enemies are rushing in from all sides, so in those situations you just need pick a spot that doesn't get you killed immediately and then just keep a close eye on your surroundings, consantly viewing towards known enemy locations to make sure that no one is getting too close to getting behind your back or anything. Try to see how many enemies are coming at you and keep a track of each one, especially the ones that seem to be running towards your direction or towards a direction you are completely unshielded from. Worst case scenario, you have to memorize enemy movement patterns (a lot of the time enemies will repeat similar patterns) and then just figure out what is the best order/way to kill enemies in. If one spot isn't working and you just keep dying over & over & over, try to find a better spot or switch up strategies.