how hard is it to 100%?

[NOT penis man gaming]

i am trying to get all achievments on hl2
so i also thought to add an extra challenge: start the game again in hl2update
my questions are:
how long does it take to 100% from beggining
what is hardest achivement

i already have "Revenge!" achivement and the achievments you get before that, as well as both of the two ravenholm achievments

[Renfrew]

Half-Life 2 is one of the easiest games to 100%, because most of the achievements are story-related and missable achievements aren't particularly challenging either. You can do it all in one playthrough apart form the submissive vs defiant achievement, but it's right at the start of the game anyway, so barely counts. How long it takes depends on how skilled someone is at Half-Life 2 and how familiar they are with where everything is.

The two hardest achievements are "Keep Off the Sand!" and "Lambda Locator", which show just how easy this game is to 100%.
"Keep Off the Sand!" can sometimes be buggy, but it's very simple to do and just requires patience. Just spam save every time you make progress in case you make a mistake.
"Lambda Locator" is harder, not because the caches are difficult to find, but because sometimes you get so focused on combat and progressing the story that you forget to look for them.

[NOT penis man gaming]

can you compare the difficulty of those two to the difficulty of zombie chopper?

[Renfrew]

On a scale of 1 to 10:

Zombie Chopper = 2 - Just remember to always have the gravity gun out and keep a saw blade with you. This chapter was made for the gravity gun, because you'll never struggle to find something to punt.
Keep Off the Sand! = 3 - Take things slow, save regularly
Lambda Locator = 6 - 45 caches is a lot of time and effort, in addition to the potential of missing one due to forgetting to look for caches

[Salander]

There's a wonderful guide here on Steam that point the location of every Lambda in the game. Is quite useful because the symbol for some of the lambda's can dissapear due to a bug.
But overall, is true that's not a difficult achievement.

[Mark 4025]

When I was a 3rd grade student, I was trying to unlock all achievements in L4D1 and L4D2, I was about to earn what are you trying to prove? and still something to prove, but it was impossible for me to earn these achievements.

[Yzal]

Easy. HL2 achievements where added years after the game was out so they couldn't go too crazy with them.

[Salander]

And that's a really good thing.
I mean, some achievements seems to be made with the sole intention of making games last A LOT longer than expected, thus overstaying it's welcome. I'm talking about those who asks the players to do some weird things like playing for straight 14 hours without dying or winning the game 3-4 times.
The ones in HL2 seems a lot more organic in that sense.

[Yzal]

Originally posted by Mapache Malvado:

And that's a really good thing.
I mean, some achievements seems to be made with the sole intention of making games last A LOT longer than expected, thus overstaying it's welcome. I'm talking about those who asks the players to do some weird things like playing for straight 14 hours without dying or winning the game 3-4 times.
The ones in HL2 seems a lot more organic in that sense.

Yeah, i don't enjoy grindy achievements. But things like "one free bullet" from ep1 i like, it's like a challenge. I don't see the point of achievements that you get just by playing normally, things like "kill 50 enemies" in a game that' gonna throw you a LOT more than 50 enemies.

[UCEY]

Most, if not all, achievements are a breeze