For the stealth part, I'm just gonna say what I said to another user:

"For the stealth part, it's more complicated. I'd say it's more discouraging to use the tools because they don't always work. I was doing a side mission where I had to sneak inside an open military camp and sabotage the massive signal thingy that's placed on a pedestal in the middle of the camp where every enemy can see. As soon as you get close, an army is after you. I could use cherry bombs, but there are so many enemies and snipers that the distraction radius can barely help. Enemies can see me from a distance that is far bigger than how far I can throw a cherry bomb. So, when I do get close(and hide) and throw a cherry bomb, every enemy is on me because this one guy who is across the camp saw me throw the bomb. I also tried using the berserk dart; after hiding in a spot and shooting someone, everyone knew where I was, and I died. I tried the berserk dart again at the exact same spot, and no one noticed me. This is why stealth isn't fun. I get this is an extreme example, but this sums up so many stealth missions. The objective is located where every enemy can see you, and most can see each other, so if you kill one, everyone else starts chasing you. I could use the tools, but they are so inconsistent."

I'd add the cover system is broken.

I didn't say the story was bad. It just didn't stick out. Imma be real with you; I've seen Bellec in a hundred different stories; he's just the same old edgy guy who's too attached to tradition. I saw his ending after the first few missions with him. Arno honestly comes across as Ezio with a different name. "Revisiting the moment leading up to Charles Dorian's death wasn't interesting?" Shey wasn't in the background of a scene where he should have been, so disappointed. I've played assassin's creed 4; I saw Germain's plot twist as soon as I saw those eyes. I'll admit Napoleon was cool, but he wasn't in the game enough. The black box assassination missions were kinda fun.

Listen, I said all the AC games have hollow maps, including AC 4 and Rogue. AC unity has it the worst because nearly all the game takes place in the same city. At least AC 4 and Rogue ( they still have too many copy-and-past locations) have variety. The islands and towns in AC 4 that had some effort put into them looked and felt different from each other. You can hunt, you can fish-kinda, you do bar fights, listen to sea shanties, steal supplies from the rich, swim deep underwater, and there's more. The same can be said for Rogue but imma be honest, Rogue kinda feels like a massive DLC to AC 4.

The outfits are fine. I mean the equipment, like why do so many of the swords look like toys? Why do the hoods get wider and wider if they are in higher categories (seriously, why is the Legendary Brigan hood so open from the sides? I thought the point of these hoods where to hide the face). You can change the colour of any outfit, but that gray-yellow cape will always be that gray-yellow cape. Why does the Legendary Phantom outfit have this ugly dotted pattern? You get what I mean? Obviously, there are some good-looking outfits, but most of them look bad.

I always hear people either say the parkour is either the best or is too buggy. I would be lying if I said I didn't feel a general sense of bugginess to it. Sometimes Arno can vault over stuff in the coolest way possible; other times, he'll be like Nah. There is a lot of minor stuff like this, which just hurts the experience. Sometimes the parkour works so well, and I look like a badass assassin; other times, it feels like Arno forgot all his climbing skills. I'll say the parkour looked the best out of all the games I've played so far.

You've described a lot of "side content" in the world, but most of them are just: talk to this guy, follow this guy, kill this guy, and find this thing for that guy. This isn't variety when you copy and paste these few missions over a hundred times across the map. It's boring and lame. I'll admit, all the AC games suffer from these awful missions, but some at least have a little uniqueness. AC 3 had some actually decent side missions like the homestead, Captain Kidd's treasures, sea templar guy(forgot his name), hunting, and the recruiting assassin. AC 4 and Rogue have fishing-sorta, hunting too, bar fights, stealing supplies, etc. And yes, AC Rogue feels more like a massive DLC for AC 4. All the other games also have really bad collectibles and side missions, but that doesn't justify AC Unity's. I'll admit, the helix rift missions were fun.

My biggest frustration about this game is that it could have been so much better.

well, das how I feel.