Serial Cleaner
28 Achievements
8-10h
Challenge Seeker
Play all Challenge modes
2.6%
How to unlock the Challenge Seeker achievement in Serial Cleaner - Definitive Guide
K4rn4ge
TrueAchievements
TrueAchievements
. This will bring up the list of challenges. Keep in mind you DO have to play all day challenges AND all night challenges even if some have the same names (they are unique). Simply load up the challenge and quit to menu and it will count towards the achievement. Rinse and repeat for the other 19 until the achievement pops. Also keep in mind that all 20 challenges are not available in the first contract which is why I mentioned the first chance to do this achievement is Contract 2.
KTKarona
TrueTrophies
TrueTrophies
The Here Comes A New Challenger! trophy in Serial Cleaner worth 20 pointsCheck out any Challenge mode
There are twenty different challenge requirements. Contract 01 offers 17 of these, but Contract 02 is when it offers you all of them; for that reason, load up Contract 02 and run down the list. Do note that you don't necessarily have to complete all of them in the typical fashion to get them counted. By that, I mean that some of the contracts require endless corpse gathering (for time boosting) or something similar; all you have to do is have a score register in the leaderboard for the completion to count.
In the Main Menu > Contracts (bonus or story) screen, press L2 to bring up Contracts and then highlight the specific one you're interested in. It may take a few seconds, but the leaderboard should soon propagate results of the ones with the best time, highest score, etc. If your name shows up there, you have played the mode and can move on to the next.
According to El Trophynador:
Actually you don't need to do any contract for it to count. Select what mode you want, load the level then quit to main menu. No need to complete the level. Repeat for all day and night challenges and it's done in less than 10 minutes.
SpaceCoresDad
(Online)
There are a large variety of challenges you can add to story or bonus contracts you have already completed but you must be signed into PSN for the challenge trophies to pop. These can be accessed by going to a contract you have completed and pressing 
. You don't need to complete any of them, simply try each one on a single contract and you are free to exit back to the main menu the second you load in. Do this with every challenge and the trophy will pop.
AlphaDynasty42
There are 20 challenges modes that add different variety to levels. The earliest you can get unlock this achievement is during Contract 2.
Go to Contract 2 and press 
. You will see all the list of challenge modes. There are two types: day challenges and night challenges. Play each one to unlock the achievement. Even though some of the challenges are the same (the only difference being day and night) you still have to play them. Take note that you don't even have to complete them. You can load up the challenge mode and then exit to main menu and still make progress towards this achievement.
DelvooD
stratege.ru
stratege.ru
