Here is the full list of all 26 Lightyear Frontier achievements.
Explore 7 ruins.
Explore the vault in Outset Grasslands.
Restore all regions in Outset Grasslands.
Remove 150 Noxious Slimes.
Remove 700 Noxious Weeds.
Plant 1000 seeds.
Build the radio tower.
Plant 500 seeds.
Get 10 upgrades at the Upgrade Depot.
Feed 50 animals.
Remove 50 Noxious Slimes.
Remove 300 Noxious Weeds.
Feed 20 animals.
Plant 100 seeds.
Explore a ruin.
Remove 100 Noxious Weeds.
Get an upgrade at the Upgrade Depot.
Feed an animal for the first time.
Plant your first seed.
Spray water at another player.
Increase Homestead Coziness to 1.
Increase Homestead Coziness to 2.
Increase Homestead Coziness to 3.
Restore a region.
Remove 10 Noxious Slimes.
Scare away 10 animals.