Here is the full list of all 12 Algae achievements.
Complete the first level of Episode 1 on any difficulty
Travel 1 metre in total
Save all possible clones in Episode 1 on any difficulty
Complete all levels in Episode 1 within the expected time on any difficulty
Create a total of 100 clones
Trick a Stalk into attacking Beany
Trick 2 Stalks into attacking each other
Complete all levels in Episode 1 on Easy difficulty
Complete all levels in Episode 1 on Medium difficulty
Complete all levels in Episode 1 on Hard difficulty
Complete all levels in Episode 1 on Impossible Difficulty
Create your first bridge