I have so much games I never completed, either just beaten the story but not done everything, or never seen the ending, and some I begin and don't think they are worth my time.
There are also games I never played much or didn't complete due to missing time because another game I wanted more was released meanwhile, and I hope one day I'll complete them! but rarely go back... I guess This is the main reason for my uncompleted game backlog.
I also tend to want to 100% collect collectibles before completing a game, and end never completing it because I miss items... Sometime I give up looking for collectible and decide to end them, some I wanted to unlock all trophies but gave up too.
there are games I would consider "giving up" due to difficulty but always hoped to complete them, but I can't. These are frustrating to let them go.
Some I remember (there are too much to remember them all for the past 35 years):
- Star Ocean Till end of time (it became too difficult, at the point where you randomly die in 1 hit)
- Zelda BotW (I completed all the quests except the DLC... and therfore never went to Ganon)
- Dark Soul III (someone gift me that game, I never played any Soul game before. and I'm bad at it. I reached chapter2.. I think)
- Furi, or Geometry wars (I like games requiring dexterity, but I guess I'm not good enough. I can probably say the same with Rythm games, like NDS Rhythm paradise, Maestro, Theatrhythm, Thumper, etc.) I wish I was better at these games!
- Kingdom Hearts: reChain of memory Floor 12 (too hard, ennemy get harder, player stays the same power. too random due to ... ramdomly gained gamecards, if you are unlucky you get only poor cards. Also, I'm bad at choosing cards fast enough and staying alive).
I wanted to play the full KH series in order, but got stuck on second entry... forever. So I never went past Chain of memory...
And so many more. Backloggery says I have 28% unfinished games of 500+ unplayed (and 300+ completed).
The last game I "gave up" searching collectible and decided to go to the ending is Kena: Bridge of Spirits.
I'm missing 1 Rot, and probably 4 chests. (and no, I don't look at guides or videos or cheat in game to unlock things for me, it's not fun)
I also wanted to play in Hard, but found the bosses quite hard, I downgraded the difficulty to normal after 3 bosses... it's a sort of "giving up" on what I decided to achieve for that game. But, I'm getting old and bad at gaming I guess.
ah, I gave up after 3 years on the only MMO RPG I played : Ragnarok online
Because, you have to decide when to stop ! and that's when I gave up on MMO in general.