Here is the full list of all 18 The Gallery - there are Episode 1: Call of the Starseed achievements.
Complete the Upper Sewer level.
Complete the Beach level.
Start a fire on the Beach.
Complete the Tutorial level.
Pick up 4 items.
Shoot 3 bells with one clip.
Spend the night in the Beach tent.
Light 5 fireworks.
Douse 6 candles.
Hold the radio on the Beach for three minutes.
Return all the starfish to the sea.
Complete the Lower Sewer level.
Complete Episode 1.
Listen to all the tapes in the game.
Blink 1000 times.
Smash 15 special bottles.
Sink 5 volleyball shots in the Beach hoop.
Complete the Laboratory level.