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