Here is the full list of all 9 Runeous: Part One achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Make Lene Unhappy
You've reached the very end that end could be!
Finish the Game
Embrace the fear!
Make Col Unhappy
Unlock the power of thought
Meet a mysterious stranger
Encounter a monster and beat it!
Make Lene Happy