Looking that are very challenging to 100%/ get all achievements, but this is due to difficulty, not length.

Looking for games where it is VERY difficult to get 100% or all achievements in, to the point where it is a bit of a brag to say you were able to.

And I’d prefer this to because of having to beat a very difficult mode, hard “Kaizo-like” levels or bosses. Not really interesting in games where the challenge is grinding for 200 hours or doing 10 playthroughs, but the actual experience is easy. I don’t mind difficult games with a bit of length to them though.

And I’d prefer something with well designed difficulty or challenge, not like spike or bullet hell type games.

I don’t mind the base game or basic playthrough being difficult, but I would like 100% to be somewhat of a step up from that. (Ex: don’t recommend dark souls if 99% of the challenge is just beating the game in the first place).