10 Most Anti-Climactic Video Game Endings EVER
Wait, is that it?

There are many video games which demand tens or hundreds of hours of emotional and physical investment. So, when the final moments don't live up to that build-up, it creates a sharp dissonance. No matter how incredible the platformer, RPG, or Soulslike is up until that point, a weak final boss or an underwhelming conclusion can dilute the entire experience.
Now, that's not suggesting every entry on this list classify as "terrible". Though these endings weren't great, they didn't urge anyone to smash their controllers out of frustration. (Basically, what we're saying is Mass Effect 3 isn't on this list.)
Having said that, there's no question certain games peaked too soon. The most thrilling character arcs or emotional climaxes might occur early in the main campaign, impairing the epilogue's impact. A boss fight halfway through may be more intense or emotionally charged than the encounter with the main villain, making the ending feel like a formality. And if there is no final boss, players mightn't feel any sense of accomplishment when the credits roll.
In situations like this, it sometimes feels like the game "ended" long before it actually did.
10. Rage

Set in a post-apocalyptic future, Rage follows a soldier called Nicholas Raine, who emerges from a century-long hibernation. After being targeted by an evil organisation called The Authority, Nicholas realises he's the only person who can awaken the rest of humanity.
Developed by id Software, you'd expect Rage to have similarities to the company's other properties, like Doom and Quake. However, the first-person shooter feels more akin to Fallout or Mad Max, implementing an open-world racing structure and action RPG mechanics. There's also more focus on exploration, vehicle combat, side-missions, and crafting, all of which are handled beautifully.
But if there's one department where Rage drops the ball, it's the ending, or lack of. The final mission involves Nicholas activating a satellite uplink to awaken mankind. Although it'd be fitting to face a terrifying boss before or after, Rage goes against the grain by having Nicholas throw down with... nobody.
Considering how powerful The Authority is, you'd expect them to have a powerhouse robot or a mutant monster protecting the one thing that secures their grip on the world. But after blasting a few standard enemies and flipping a couple of switches, Nicholas will find he's defeated the malevolent empire.