You finally stop The Bad Guy (TM), then he comes back as A loving DRAGON, and you stop him again. Then a spooky evil demon mask of power tries tempting you into putting it on so you can become The Bad Guy 2.0, but then a previous antagonist comes in and it magically turns out he isn't an antagonist because STORY and tries to convince you to not put the mask on because ITS loving EVIL and if you are a good little boy you toss the mask into the lava because that destroys it I GUESS?
Fable: The Lost Chapters
You're left stranded on a planet as the only member of your squad that's still there, while your only other squadmate leaves with the IMPORTANT CARGO that will help a CERTAIN CHARACTER in the "FUTURE" GAMES, and you have to FIGHT OFF THE ENEMY with totally stuffty underpowered as forget human weapons respectably acceptable human weapons (unless you just relieve an alien of his), and serve as THE ULTIMATE DISTRACTION while your last remaining hope for escape zips away because YOU CHOSE TO STAY because YOU ARE A loving MARTYR, and that whole SPOILERIFIC AS stuff opening cinematic begins to make sense near the end when you finally SUCCUMB TO YOUR cripplingly horrible skills OVERWHELMING ENEMY OPPOSITION, and your face is thoroughly caved in by a bunch of ALIENS WITH SPACE SWORDS AND SPACE GUNS.
Halo: Reach
You finally come to the top of the SUPER SCARY DEMON TOWER to fight off the BIG BAD with the magical power of ALTERNATE PERSONALITY(ies) DISORDER, and are forced to go through a MULTI-STAGE BOSS FIGHT (shudder), where the POWER OF FRIENDSHIP saves the day because YOU ARE LITERALLY JESUS. Then you spend your final hours loving ABOUT THE TOWN with a HORRIFICALLY WHITE BORDER on your screen while SAD MUSIC is playing dramatically, talk with the people you GREW CLOSE TO, then witness the final cutscene where you seriously die right before your friends show up to greet you again and you loving cry your eyes out because its loving SAD.
Persona 3
After trekking through YET ANOTHER SUPER SCARY DEMON TOWER to BRING BACK YOUR BEST FRIEND, you finally reach the FINAL BOSS who looks like the OTHER FINAL BOSS except HE'S loving PURPLE AND GLOWY AND stuff and using the strength you gained from EXCESSIVE FARMING AND GRINDING, you DEFEAT HIM because you are clearly SO BADASS. And then absolutely nothing happens. You go back to town because you are confused as stuff as to why there was no ending cutscene or no sudden tying of that loose end, but then it turns out OH WAIT YOUR BEST FRIEND IS BACK ALL ALONG, WE WERE JUST loving WITH YOU, PLAYER. And then you get LIKE ONE LINE OF DIALOGUE FROM THE PEOPLE OF THE TOWN FOR SAVING YOUR FRIEND, and then your mystical feat is FORGOTTEN because DEVELOPER CONSTRAINTS??? forget.
Rune Factory 4
The Grox kill you.
Spore
After having spent by now HOURS AND HOURS of designing VEHICLES(?) you finally come to face the BIG BAD in the final SHOWDOWN where you both must DO A BUNCH OF ARBITRARY CHALLENGES THAT MAKE NO TANGIBLE SENSE, then finally OF COURSE YOU WIN, because you are the PROTAGONIST. You start wondering to yourself "GEE THIS IS KINDA LAME TO BE SUPER HONEST" but oh well because now your ARCH RIVAL is now spending the rest of eternity in a FORCED LABOR OCCUPATION because SOMETHING SOMETHING PLOT, and you now have the WORLD AT YOUR FINGERTIPS and now you must BLINDLY SEARCH FOR SOMETHING TO DO now that THERE IS NOTHING TO DO. SOMETHING. ANYTHING. forget.
Banjo Kazooie: Nuts and Bolts
I love doing these. I might make more.