Regarding collectables-based challenges, in my experience, all collectables that don't unlock content or aren't some kind of upgrade are a waste of time.

I remember collecting all the figments in Psychonauts 1, how frustrating and time consuming it was and how it was near useless to the regression of the game. I love Psychonauts and I would like to play it again over and over, but I would not collect those pesky figments ever again.

Any "no death" achievements/challenges in souls-like games. I don't see a point in struggling for weeks/months just for a small badge on my account.

On the other hand, 100%'ing certain games like Stardew Valley is definitely worth it. I won't spoil what happens, but just know that it is worth doing.

Completing the Pokedex is pretty cool.

I've come close to getting all the capsule toys in Shenmue but in the end it was a lot if reloading saves and eventually I gave up. I barley finish any games so doing extra challenges is even rarer for me :/

I do challenges for the fun of doing them, not for the reward.

Dark Souls at level 1 is absolutely worth doing if you're replaying the game. It's a lot of fun, and much easier than you'd think during your first time playthrough.

Surprisingly enough, playing Getting Over It 50 times over for the achievement is one of the most fun experiences I've ever had. The skill curve is just awesome to experience, my time dropped from 18h all the way down to 10 minutes.

Challenge not worth doing : all achievements on Rayman Legends. The game itself is amazing, but to get the last achievement you need to play daily procedural levels for MONTHS unless you're a god at the game (and I'm pretty sure the top times are always cheated anyway, so you're never getting the highest point reward anytime ever)

I hunt down achievements when I enjoy the game and the achievements sound fun and not busywork. If it's interesting side quests, minigames, or fun challenges, I almost always do them. I also like playing at max difficulty when it's fair.

If it's about going through a checklist to collect 100 feathers or spending 50 hours learning the entire game by heart to complete some hardcore challenge, I'd rather do something else with my time.

Anything involving multi-player is just completely ignorable.

Collecting every item in Rabbids Go Home.

Stupid game made me think there was a secret moon level. I feel like the devs actually forgot to put in at least a trophy or something because it unlocks nothing.

I have the "Completionist" achievement for Half-Life2 cause it was a fun challenge to get them all (yes even the gnome one), but gave up on Osmos: fun and relaxing game, but the last levels were too much hassle.

I didn't do all the optional bosses in expedition 33. I finished the plot and was so powered up the story bosses didn't even get a turn. But fighting the billion hp "dodge 13 hits in a row or die" just wasn't fun for me.

I draw the line at whether it's something that can be done naturally, as a result of playing the game and enjoying it enough to put in that much time. I'll entertain trying to 100% a game that has an achievement to farm 1000 of some herb, if it's something that I'll just come across in due time by making full use of all the game mechanics, and presumably see some form of in-game payoff for my efforts. I'll instantly become content with just seeing the credits if an achievement to get a similar quantity of something is just an excuse to pad play time by making me grind some monster drops just for the sake of getting that last achievement.

That one insane hour-long-wait shape trace in The Witness. Respect if you completed that one, not worth it for me..

I 100%'ed Tony Hawk Pro Skater 2. That was pretty fun with secret characters and levels to unlock.

Filling out your arsenal with adversary weapons in warframe gets easier the more you do, and a lot of them are really worth while... but maxing them out? Hell no, that's 5 forma a pop, and the valence bonus is NOT worth re-grinding out. I'm glad DE has made the Infested Adversaries easier to deal with, so the valence bonus is easier to max out but good god. that's too much forma.

I mean, it‘s videogames so any challenge that gives you the satisfaction of clearing it is worth it, any that doesn‘t isn‘t worth it. Could mean all of them are, could mean none of them are, and could mean anything inbetween. I‘m an achievement hunter so I go for those, but I‘m not super purist about it; if the challenge is to walk 40000km, I rubberband the controller lol

I'll only answer the first one.

Achievement systems full stop. People who value completion through achievement systems are fucking uncreative persons who need to find a different hobby or reconsider why they enjoy theirs. From a dev standpoint it's just a way of lazily padding a game.

I'm not talking about completionists of actual game content like collecting all the stars in a Mario game, or catching the 151 pokemon, but moreso the "silver trophy" for killing 2000 grunts or whatever bs achievement ideas they decided to arbitrarily create. You're diluting the art form.

Completing entire tech tree in minecraft modpacks. For those who dont know, many popular modpacks for minecraft has a questlines, usually its main progression chapters, explaining how to play the game, and many secondary queslines for specific stuff or mods. And many of this mods are optional for the main progression, so completing them or even using them at all is just useless extra work.