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