Here is the full list of all 50 ELEX II achievements worth 1,000 gamerscore. It takes around 50-60 hours to unlock all of the achievements on Xbox One.
"Nothing to Lose" completed.
"Billy Idol Concert" completed.
"Strong Alliances" completed.
C.R.O.N.Y. U4 found.
Wardek found.
"Old Love Doesn't Rust" completed.
Joined the Berserkers.
Joined the Clerics.
Joined the Outlaws.
Joined the Albs.
Joined the Morkons.
Decided not to join a faction.
Raik forgoes his salary to benefit the Cultivators.
"Hitch and the Three Investigators" completed.
"Smuggling Toys" completed.
Decide Irissa's fate.
Discover the secret of the old map.
"Khan's Execution" completed.
ELEX II completed.
300 missions completed.
All combat skills learned.
All survival skills learned.
All crafting skills learned.
All character skills learned.
All Jetpack skills learned.
Level 20 reached.
5 companions in your party.
Teleported 20 times.
20 Audio Logs found.
30 potions brewed.
Made a weapon 20 times.
Fuel capacity increased to at least 30.
Unlock at least 35 teleporters.
Collect 10 map pieces.
100 locks picked.
30 successful hacks.
20 merchants found.
1,000 elexit shards received.
10,000 elexit shards received.
50,000 elexit shards received.
Healed by potions 100 times.
Collected 100,000 items
Destruction is below 10.
Destruction is over 90.
20 monsters killed.
20 Skyands killed.
30 innocent creatures killed.
10 kills by hand grenade.
200 monsters killed.
500 monsters killed.