Here is the full list of all 20 MC Lars: The Video Game achievements.
Earn all 36 stars in all 3 worlds.
Earn 3 stars in a level as T-Rex Lars.
Complete the final level.
Complete the eleventh level.
Complete the tenth level.
Complete the ninth level.
Earn 3 stars in a level as Emo Lars.
Complete the eighth level.
Complete the seventh level.
Complete the sixth level.
Complete the fifth level.
Earn 3 stars in a level as The One.
Earn all 12 stars in a single world.
Complete the fourth level.
Complete the third level.
Earn all 3 stars in a single level.
Complete the second level.
Complete the first level.
Clear out your data and start from scratch.
Complete the tutorial level.