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