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