I found your post somewhat lacking and wholly half-assed.

NES Robin Hood, mainly because it turned out the game has no save feature, and it's too long to lack a save feature, especially with the game being somewhat RPG-ish.

While I never got to play it, Ultima 5 NES was a letdown, after the excellent Ultima 4 NES. Thing is, my brother is the one who got the game, and (unlike Ultima 3/4 NES) the game has only one save slot. From what I watched, however, the game just wasn't that good, and in fact is pretty bad.

Also, Castlevania 64 felt like a letdown when I reached the end of Easy mode. After going through a frustrating level where you have to carry an item that will explode if you get hit even once or fall even a short distance (the sort of frustrating task that shouldn't have been in the game in the first place), the game hits you with "this is the end of Easy mode; if you want to see the rest of the game, start over on Normal mode". (It's not even a real ending.)

Also, Link's awakening and the Nintendo 64 Zeldas, mainly because they lack true final dungeons, and are a bit too puzzle focused for my tastes. (Also, insta-fail stealth sections, first appearing in Ocarina of Time.)

I could also mention Secret of Evermore, with its rushed endgame, not giving the player a chance to level up late-game spells.

Final Fantasy 7 as well (and to a lesser extent FF6); FF7 took the bad aspects of FF6, threw out the good aspects (no non-linear second half), made some other changes for the worse (shrinking the party size and forcing a specific character into the party for basically the entire game), and doubled down on things like cutscenes. Also, it didn't help that I played the PC version, with its long load times and occasional crashes and infinite loads, making the game even more frustrating.

Edit: Why the low rating?

My biggest letdown(s)...

Mafia III.

The first two installments are some of my favorite games of all time... but... the third was -- IMO -- a waste of time and effort. It was monotonous, lowered the main character to little more than a serial killer bent on revenge, and disrespected characters. I loved the time period and I have no problem with racial issues explored in games, but neither were explored in any but in the most base of ways. Where 1 and 2 felt like classic mob stories, 3 felt like 60's and 70's schlock "blaxploitation." (borrowing a film studies term) Very disappointing.


Red Dead Redemption II

RDR II feels -- to me -- like an almost total failure. Mechanically, it's a chore to play -- between clunky imprecision (more than RDR I) and purposeful micro-mangement . Story-wise, it takes forever to build any narrative momentum. And while beautiful to look at, there are no locations in RDR II as iconic as even the least of RDR I's locations -- which all seem ripped from classic Westerns. In the end it all just felt half-baked and terribly pretentious.

Although not one of my biggest letdowns...

Castlevania Lords of Shadow II

I Absolutely loved the first game and still think on it often. But 2 was a mess. It wasn't completely horrible, but certainly lost most of the charm of I. I only really enjoyed one of the dlc... the rest was more of a chore. Yet... the first game was so good IMO that I'll weather II for a bookend of the story

Command and Conquer: Tiberian sun. Was extremely hyped back in 1999, turned out to be a very mediocre game, with boring campaigns and very unbalanced units.

A game can only be a let down if you had high expectations that were not met.
So according to this definition, a good game can be a let down if you expected more from it than it actually delivered, and a bad game can be a good surprise if it offered more than you expected from it.
It's all in the eye of the beholder, or the mind of the player, as the case may be.

Why buy/play a game if you think it's bad? I wouldn't, my time and money is valuable.

I finally find someone who agrees with me on this, You mention this anywhere in the C&C community and they will drive you out with pitchforks, hell a guy blocked me after saying "TS saved my family! how dare you!"

Darkest Dungeon
RECENT REVIEWS: Overwhelmingly Positive (1,897)
ALL REVIEWS: Very Positive (73,634)

then i tried out , this game is garbage a total waste of time, a randomized punishment to make you suffer and rage
totally the opposite of what a game should do to you One of the best games ever:P

I don't know, I can't believe it's that uncommon a sentiment, imo the flaws were pretty obvious, all the more so when compared with other major RTS games released in about 1998-2000, like Starcraft or Age of empires 2.
Have to admit though that I only played Tiberian Sun in Multiplayer once, and that was in its unpatched state. I think some of the most glaring imbalances (like the NOD artillery being so strong and accurate that any ground assault against them was suicidal) were later somewhat mitigated in a patch.

yup nod arty is oppa

Orca bombers were also overpowered imo, all the more since NOD didn't have efficient mobile anti-air units in the original game version (those rocket infantrymen were horrible).
Led to some bizarre stalemate situations in the games I played against a classmate shortly after release...GDI couldn't assault a NOD base, because NOD artillery would destroy anything before they had even reached the base. But NOD units away from their sam sites would just get obliterated by Orca bombers.
So it usually came down to "trick" strategies, like infiltrating engineers into enemy bases (NOD had an advantage here with their subterranean APC), capturing the construction yard and then immediately selling it, ending the game. Wasn't my kind of fun tbh.

GOG's Lords of the Realm 2. It didn't work quite right. Messages were really fast. Battle speed wasn't quite right. Multiplayer was not possible (un-noted desyncing and no messaging).

World of Warcraft. I put a stupid amount of money into it and thought that it was a fairly.poorly crafted RPG. Guild Wars was far better for far cheaper. I was really disappointed with GW2 also, since it felt so much like WOW.

Thief 3. I actually liked 4 a lot but wish they removed the sex.

Tales of Symphonia. Gamecube one. I like the Tales of games but this one had an early boss battle that I just couldn't beat.

Last of Us:
I got influenced by the hype a bit, so when i discovered the characters were pretty much the only part of this game which was great I was kind of disappointed.
I wasn't sure if i could call it a letdown, it's between that and a "hm, that was somewhat okay"-impression depending on the part of the game.

Horizon Zero Dawn
At first the game even surpassed my expectations, but the longer i played the more obvoius the wasted potential became clear.
Battles become boring after the first time you ancounter a new kindo a enemy and became an actual annoyance later in the game.
The Story was mostly painfully predictable.
The Characters were forgettable for the most part and those who weren't only matter inside their own quests and are completely ignored afterwards. I've played MMOs where characters where handled better, that's just sad...
Overall the impression I finished the game with was "Wow, that was... average at best".

Final Fantasy Remake:
I didn't even have high expectations in the first place and it still felt underwhelming.
The Battle-System felt "clunky", I don't know a better way to describe it.
The whole game is stretched to an extend the One Piece Anime would get jealous (with crouch through, or walk after someone else really slowly parts and a load slow environmental "puzzles")
Stil completely linear.
Most filler episodes were noticebly worse when it come to writing.
The other added stuff and especially the ending, wtf?! And it doesn't even make sense within the game.

Star Ocean 5:
Yeah, I won't even explain this dumpsterfire...

lol
I'll try not to hype it up so bad the next time.