Initially captivating with its atmosphere and sound design, unfortunately once you fully understand it's game mechanics it goes back to bordering on tedium like many of the FNAF games (at least this one is much better than FNAF 3).
I do like how much the game uses sound, with it being possible to beat the game fully blind (so much so that it is a challenge run in-game). Unfortunately this requires me to turn up my volume considerably, leading to my ear drums being blown out whenever there is a jumpscare. Which is both a pro and a negative.
This is the final in the quartet of classic FNAF games. With it's vague story and entertaining side content.

Overall, I enjoy the idea of this FNAF game but don't so much enjoy playing it.

Siege used to be a significantly better game, however since it is owned by Ubisoft it is slowly being run into the ground.

The focus on competition over fun has led to many horrible changes.
The lore is some of the worst I have seen in a mainstream game, it makes no sense and it's a pathetic attempt at a story. The lore doesn't align with the gameplay at all, like if Deimos is a villain why can I play as him? Not to mention this entire Stadium Bravo thing makes no sense, aren't they supposed to be a secret organisation? Why are they in a stadium? What?

Here are some of my pre-existing problems, lots of which have gotten worse: crap community (go into a quick match it is so incredibly dead), performance issues, bugs (too many to list and only the fun ones get removed, I constantly have issues where the game just won't let me access voice chat even though I'm not banned, I had to get a new PC to fix this at one point and sometimes it still doesn't work), connectivity and server performance (how hard is it to get me to play with friends), etc.
Another issue is the game's slow move away from a "realistic" tactical SWAT game to the fuck-off sci-fi POS it is now. They used to try and make operator gadgets somewhat realistic or explainable and now they have given up. The theming of the new maps suck too. The old maps like Bartlett, House, and Oregon tried to represent more realistic SWAT scenarios and now we have maps like Nighthaven Labs and Lair or even cow turds like Stadium Bravo or Stadium Alpha. These maps shouldn't be in the game, because they make no sense and a lot of these are hated by the community at large.

In general most of my new problems with this game stems from the fact that Ubisoft prioritises competition over enjoyability. They try so hard to balance the game, that they have balanced the fun right out of the game making the casual experience boring and the competitive experience horrible. In general if something is too viable or too used or too fun, Ubisoft nerf it. They almost always choose to nerf something over buffing it to balance the game. This has resulted in awful and sluggish gun play, making it horrible at a competitive level. Ranked 2.0 is regarded as one of the worst changes in the entire game, and is hated by almost everyone including myself. They have also made several changes both directly and indirectly making the game less fun, ruining the casual experience.
So... competitive players have less fun and casual players have less fun... but at least it's "balanced" right guys!!

I myself am a casual player, I just wanna have fun playing the game. I will now list several changes as examples of things that have directly or indirectly made the game less fun, some of these will seem miniscule but you need to understand that each change removes fun ideas or things to do, and I also have many more I didn't want to list here because the yap levels are already way too extreme. Starting with the two biggest offenders (your opinion my choice):
- First, the shitty changes to the gun mechanics. Yes, early I said this affected competitve players but I know it affects casual players too. There is a reason why I have started playing shields OPs significantly "recently" because running around and getting melee kills is much more fun than the shit that is the gunplay.
- Second, the changes to recruit. Recruit rushing is an iconic and hilarious past time and is iconic to the Siege experience. First they removed shields from Recruit, then they outright said "fuck you" to the entire community and "reworked" them conveniently removing Recruit rush... What the hell? What was the need to remove multiple people picking this? It was only a thing in quick match WHY SHOULD IT MATTER. This is the one I am most passionate about, it was one of the last exciting things I could do in this game and they found a way to remove it. Fuck you Ubisoft you fucking fucking fucking fucking FUCKS!
- Next, any fun strategy I can think of gets directly or indirectly removed. Throwing cams outside, spawn-peeking in casual, recruit rush, goyo canisters around the hostage, holding frag nades and running up to people, etc etc etc etc etc etc, think of a fun strategy or technique and eventually it is gone, fuck you. All I have now is Plane and the Kebab stand on Favella.
- Shit events. The events recently have been shit. I mean they even found a way to ruin Doctor's Curse, how do you do that? The bathroom strat was way too powerful, and instead of making a multiple of simple changes I could think of to fix it they just said "fuck you" and made it so you couldn't go into that bathroom at all instead of fixing the core problem of the event. THANKS UBISOFT.
- The removal of T-Hunt and Situations is one of the most fucked up things they have done. T-Hunt and Situations were so fun, and it was great to play them whenever my friends needed to take a break or in general when I was just waiting for something. They weren't just fun for waiting around or as a break from the main game, they were also great with friends over all. I expected the removal of this but it hurt so much. Also the new AI I don't really care for, even if they get them to be realistic (right now they are shit) I couldn't care less and would've prefered if they kept (or even expanded upon because yes you can expand upon old features Ubisoft) T-Hunt instead of removing because "it took too much work".
- The reputation system, is so boring. You can't do anything fun because you'll get reported for "griefing", fuck you! Also before we had friendly, toxic and boring (non-responsive not listening to voice chat) players. Now all we seem to have is the occasional toxic player and the other 90% are just boring, especially in casual.
- No seriously, in casual nobody talks. You say something in voice chat or in the game chat and most of the time there will be one or MAYBE two respond in the game chat. I'm lucky to have ANYBODY talk in voice chat in quick match anymore. Yes this isn't directly Ubisoft's fault but it is still a problem.
- Removal of old but exciting maps. Bring back Bartlett University, bring back old pre-reworked maps, even if it is just in quick match.
- Finally, making the game much more ugly. They have consistently made changes to "balance" the game while at the same time making the game look like horeshit. Things such as removing corpses (removing the ability to hide in corpses which was great fun), or removing night maps (bring them back in casual PLEASE).

On top of all of this: Ubisoft are offering less content each season, spending their time developing a skin marketplace, the cheating problem has gotten worse... AGAIN (I am getting cheaters in quick match now, not a joke), and they have the absolute BALLS to announce a membership (don't buy it).

And at the end of it all, Siege is at an all-time high in popularity. We full well know it is not because of this game or because of Ubisoft who have only found ways of sucking the life out of this game, it is because of content creators like Jynxzi who have revived this game.
Please please Ubisoft, make a switch to making this game more fun. Or it will die. Content creators can only carry it for so long. I can't remember the last time I had fun in Siege playing the game seriously outside of aces and insane clutches, it is boring af playing the game normally.