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 Happy
Make Lene Unhappy
Encounter a monster and beat it!
Meet a mysterious stranger
Unlock the power of thought
Make Col Unhappy
Embrace the fear!
Finish the Game
You've reached the very end that end could be!