Here is the full list of all 19 Obscure II Obscure: The Aftermath achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Finish the game.
Obtain every available weapon during a game.
Jedidiah won't make any more trouble.
Consume 10 energy drinks.
Get to the main yard at Leafmore.
Heal a teammate 10 times.
Find Sven.
Get to Jedidiah's house.
Find Amy at the Fallcreek dam.
Recharge electric weapons 10 times.
Go through the hospital.
Open a chest.
Find Jun.
Find Corey's car and get to the hospital.
Meet up with Kenny and Amy at the Delta Theta Gamma party
Go to the Delta Theta Gamma party.
Over-consumption of tea is not recommended.
Open all of the chests.
Prepare a serum, an improved serum and a powerful serum.