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