Here is the full list of all 14 Realm Grinder achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Unlock the Mercenaries.
Reincarnate once.
Find 10 Artifacts.
Unlock Archeology.
Cast 500 spells in a single game.
Gain 1 Gem.
Unlock the Automatic Casting upgrade.
Produce 10.000 mana in a single game.
Build 100 buildings in a single game.
Find 50 Faction Coins in a single game.
Click 100 times in a single game.
Gain 1.000 Coins in a single game.
Have 500 Assistants.
Unlock the Dragons.