Here is the full list of all 157 UFO Online: Invasion achievements.
Complete all quests of “Illegal investigations” series
Gain level 2
Gain level 5
Gain level 10
Gain level 15
Gain level 20
Gain level 21
Kill 1000 monsters of your level or higher
Kill 10000 monsters of your level or higher
Kill 100000 monsters of your level or higher
Kill 150 unusual dogs of your level or higher
Kill 200 unusual cistopods of your level or higher
Kill 150 unusual flies of your level or higher
Kill 150 unusual stingers of your level or higher
Kill 450 unusual denticulats of your level of higher
Kill 450 unusual spitacids of your level of higher
Kill 400 unusual transgenant of your level or higher
Kill 400 unusual megacephals of your level or higher
Kill 350 unusual silikrids of your level or higher
Kill 350 unusual sectoids of your level or higher
Kill 700 unusual rictopods of your level or higher
Kill 700 unusual necrophags of your level or higher
Kill 700 unusual guardians of your level or higher
Kill 700 unusual enforcers of your level or higher
Kill 700 unusual infected soldiers of your level or higher
Kill 700 unusual infected storm-troopers of your level or higher
Kill 2000 unusual engravers of your level or higher
Kill 2000 ixomorphs of your level or higher
Kill 50 monsters of your level or higher with one shot
Kill 250 monsters of your level or higher with one explosion
Complete all quests of “The other side of power” series
Complete all quests of “Hidden threat” series
Complete all quests of “Hooray! Treasure!” series
Complete all quests of “Water for the wastelands” and “Cleanliness is the guarantee of health” series
Find 25 stashes of unknown stalkers
Complete quest “Reliable partner” 50 times
Take a prize in Meat grinder unclassed
Take a prize in Meat grinder among top 3 winners
Classified data
Use 100 mega docs (excluding bound ones)
Use 100 adrenalines (excluding bound ones)
Use 10 resuscitators (excluding bound ones)
Use 10 neuroboosters (excluding bound ones)
Use genetics 30 times (excluding one you got from NPC or used a certificate to get)
Use reset skills 5 times (excluding one you got from NPC or used a certificate to get)
Install unique avatar (excluding one you get with a certificate)
Use storage expansion 10 times (excluding one you get with a certificate)
Use binoculars 10000 times (excluding bound ones)
Give 100 gifts to other players
Play UFOmania 100 times
Play UFOmania 1000 times
Play UFOmania 10000 times
Manufacture 10000 medicinal drugs
Manufacture 100000 ammo
Manufacture 100 weapons or shields
Manufacture 100 armors
Dissociate 10000 organic materials into compounds
Dissociate 10000 fossils into compounds
Collect 100 repair kits
Repair 100 items
Find and research 100 anomalies
Get 100 modifications done
Modify a weapon up to fifth level with the same modification types
Modify an armor element up to fifth level with the same modification types
Open 1000 replicator's capsules
Get 10000 trade operations done in a store
Receive -5 carma
Receive +5 carma after -5 carma
Heal with medikits 1000 hit points
Use 1000 stims
Kill 500 monsters of your level or higher with a gun
Kill 500 monsters of your level or higher with a submachine gun
Kill 500 monsters of your level or higher with an assault rifle
Kill 500 monsters of your level or higher with a machine gun
Kill 500 monsters of your level or higher with a sniper rifle
Kill 500 monsters of your level or higher with a shotgun
Kill 250 monsters of your level or higher with a grenades
Kill 250 monsters of your level or higher with mines
Kill 150 monsters of your level or higher with a last bullet (for multishot weapon)
Win 50 battle with monsters of your level or higher when you have got 2 negative effects
Win 100 battles with monsters of your level or higher without any damage
Heal 1000 a player in your team with medikits after the battle with monsters of your level or higher
Die in 1000 battles against monsters of your level or higher
Win 100 battles in the arena against an opponent of your level or higher
Kill 20 characters of your level or higher when you have a kill right
Hug 100 snowmen in a full costume of Santa Clause or Snow maiden with a snowlauncher
MED_RATIONS
Win 10 battles against monsters of your level or higher with 0.1 health
Escape from 100 battles with monsters of your level or higher
Break 50 sawed-off shotguns
Break 10 items in battles (excluding free ones or ones taken from the warehouse)
Gain martial spirit of fifth level
Gain martial spirit when you have less than 5 minutes left of your current martial spirit
Gain martial spirit of fifth level 10 times in a row (martial spirit effects should not be interrupted in process of doing it)
Leave Citadel
Go to low security area
Go to the wastelands
Open all regions on all maps of the world
Visit all available sectors of map A
Visit all available sectors of maps A and B
Visit all available underground sectors
Visit all available sectors on all maps of the world
Save 50 stalkers you come across
Find all the containers with items available in the world
Study all archive parts
Open all towns on map A
Open all towns in the world
Visit all laboratories, factories and workshops on map A
Visit all laboratories, factories and workshops in the world
Open all entries in mines on map A
Open all entries in mines in the world
Meet all the main locals of the world
Complete 20 “UFO found” missions
Complete 50 “Invasion” missions
Complete 25 “Terror” missions
Complete 10 “Xenolab” missions
Complete 50 missions
Complete 250 missions
Kill 100 Nazi zombies
Kill 10 Iron Hanses
Complete all quests of “Outpost” series
Complete 25 “Underground menace” missions
Find 25 hidden mad miners' stashes
Find random encounter “Abduction“ 10 times
Find random encounter “Infested ones” 10 times
Find random encounter “War goes on” 10 times
Find random encounter “Incubator” 10 times
Find random encounter “Hidden depths” 10 times
Manufacture 10 implants
Manufacture 250 implants
Find and explore 10 anomalies
Find and explore 1000 anomalies
Find and explore 250 "Trophy" type anomalies
Find and explore 250 "Flycatcher" type anomalies
Find and explore 250 "Repair bot" type anomalies
Find and explore 250 "Replicator" type anomalies
Spend 50 gold in the premium shop
Spend 500 gold in the premium shop
Spend 5000 gold in the premium shop
Find random encounter “In the name of Science” 10 times
Gain level 22
Gain level 23
Gain level 24
Gain level 25
Complete all quests of “Spectral shift” series
Find random encounter “Generator” 10 times