THIS IS AN OPEN SPOILERS THREAD. PEOPLE MAY SAY THINGS ABOUT GAMES YOU HAVEN'T PLAYED.
You've defeated the Ice Wyrm, climbed though the crumbling remains of their ice fortress, and now stand atop a mountain! Behold in your sight, the glittering crystalline chest!

Your plunder?! A rubber chicken that's shaped like a hat, but actually can't be worn. It isn't vendor junk so it just sullenly sits in your inventory for the rest of your game.

Moments like this can deflate a game, causing what should be an epic journey to go rocketing back towards reality.

Two lame moments that stand out for me is the reveal of Zant's controller in Twilight Princess, because GUESS WHAT, IT'S LITERALLY GANONDORF AGAIN. Zant goes from genuine intimidation to a headless chicken in moments. Instead of doing something clever, it is at this point the plot clearly becomes Ocarina of Time: Do it Again.

Then there's the wedding of Johnny and Meyrl in Metal Gear Solid IV: Guns of the Patriots. The joke character who shits his pants gets married to Colonel Campbell's daughter. It's completely forced in during the already rushed ending, and even among the many other embarrasing and weird scenes, this one is easily the lamest.

I've given two examples, how about you name, explain and shame some?

Edit/Addendum: Can entire games be lame?

Yes. For example, Metroid OM (MOM, GET IT? SUBTEXT!) is a character assassination in longform of Samus Aran. But if you're going to name entire games, you will be needing to take us though the paces, and not just saying Chicken Shoot is lame, because of course that's lame.

*** SPOILERS ***

The ending of Evil Islands could get one of these prizes too. For one, if you haven't figured out the supposedly big revelation about who you are by then, something's seriously wrong with your reasoning abilities. And from a gameplay perspective, you simply have full crystal gear, better than anything else in the game, handed to you and can craft it as you want just for the final battle. Felt weird.

Beating a dead horse, but the ending of Mass Effect 3.

Hey you know how you made all these cool choices? Well they have NO effect on the ending! You get to choose between 4 colors! ( I know there's a secret ending, but that does not count ;) )

Yes they fixed it somewhat in an update, but the whole endgame of the series was terrible.

Mass Effect III seems to have a lot of "Huh?" moments. Such as the ninja. Or the nightmares about the little child nobody has a reason to care for.

The sad ending of Bioshock Infinite.

You do everything right, save so many lives only to get killed by the girl who happens to be your own daughter.

FACEPALM.

While this is based on opinion, one big case for me was...

[spoiler]

River City Girls
Specifically the ending.
Most random ending possible.
To me, it felt like the devs didn't know how to end the game, so they just ended with whatever (and either made the protagonists the villains in the last minute, or it was all a dream, and either way, it felt like a very cheap plot twist).

[/spoiler]

And I know GOG's forum doesn't have a way of hiding spoilers. This is a barefoot essential's custom formatting, and will appear hidden for those that use the script.

Edit: how the spoiler looks with the script on (attached image)

Gameplay:

You're playing a Dragon Quest game, and you encounter a Metal Slime, only for it to ambush you and run away in the surprise round. (Starting in DQ8, they no longer run away during the surprise round, but still have the normal chance of running afterwords.) (Edit: For those unfamiliar with the series, Metal Slimes are low HP, high defense enemies that like to run away, and which award large amounts of XP if you kill them before they can run.)

Story:

Through the early Might and Magic series, you've been chasing a villain named Sheltem, who makes appearances in MM1, MM2, and MM5. So, at the end of MM5, you approach him, and, instead of being an epic battle, all you get is a cutscene that shows an NPC killing him; you don't even get to fight him yourself after all the games you spend hunting you down.

Another one happens in The Dark Spire, where the third and final ending culminates with what's described, via text, as an epic battle, but you don't actually get to fight it (and this is after having to spend time farming money to improve your party member's CH stats high enough to reach this point).

Kane & Lynch 2 ending. All this drama and killing for... credits??? This is the lamest ending I've ever seen, even worse than the above mentioned Evil Islands.

This sort of thing happens in randomizers all the time. You travel the land, gather the three pendants, go to the pedestal, pull the treasure, and all you get is a single rupee! (Or, perhaps, a small heart, but it does you no good because you're already at full health.)

Meanwhile, you're exploring a well with a bunch of chests that in vanilla usually hold minor treasure like rupees, but perhaps you instead get silver arrows (final boss's weak point), the hammer, the hookshot, or any of a number of powerful treasures.


One other moment that some people see as rather lame (though it made me nervous that the game had crashed), this time in SaGa Frontier:

* So, as Blue, you've become a master of all magic, and you then travel into Hell to fight Hell's Lord. Here there is an epic battle (which you actually get to fight) with awesome music, so you fight for a while, and then...

* The game appears to freeze, in the middle of one of your attacks. After a bit, the screen starts changing to grayscale, after which the message "THE END" appears, and that's the end of Blue's quest in SaGa Frontier.

There is that moment when the fearsome Reapers in Mass Effect 2, whose form is an 'enlarged and enhanced' take of an (at inception) extant species, are revealed to now come in a humanoid robotic variant that look like something out of a cartoon. For me, ME and its successors were all about immersion. Seeing that comical humanoid Reaper clamber over the edge of that assembly hall floor (or whatever it was) ended all immersion in an instant.

The ending of first Star Trek: Elite Force game did it for me. It was just one really big bullet sponge with a whole lot of annoying enemy spawns. It was probably the first game I quit out of sheer boredom.

The way Fallout 3 ended your game after the MQ before the expansions came out. That sort of an approach worked for the classics because of the narrative RPG approach but not for a sandbox RPG the way Fallout has been from 3 onward. It also annoyed me that NV did that and never actually issued a fix, requiring mods to play it after finishing the MQ. That one makes a LITTLE more sense given the fact that the expansions and DLCs were all interwoven into the narrative of the base game but still, it still annoys me to this day if I finish a NV playthrough without a mod that lets me continue to wander the world and reap the benefits of my adventuring.

The "Joker Virus" in Batman: Arkham Knight was definitely a facepalm moment for me. They couldn't be any more obvious about how desperately they wanted an excuse to keep him in the game even after he died in Arkham City.

You've just run rings around and genocided the legions of hell, but are stopped short when you can't jump over a foot high obstacle.

You're playing the computer role playing game expansion called Tribunal, as this lying, conniving bitch Almalexia is pushing you around and you never get the dialogue option to state the obvious.

You're playing the computer role playing game expansion called Knigts of the Nine. The quest giver asks you if you have fame, and since you are honest and lawful good knight and have 5 Fame, you tell him yes and are denied the quest that calls for an honest and lawful good knight.

You have killed 396 hairy berserkers in Harkyn's Castle, kick in the wrong door on your way to the Review Board and
You meet death itself in the form of
1 Hobbit