Here is the full list of all 10 Atomic Adam: Episode 1 achievements.
Awarded when the player reaches 500 dead dudes!
Awarded when the player reaches 1000 dead dudes!
Awarded when the player reaches 2500 dead dudes!
Awarded when the player reaches 5000 dead dudes!
Awarded when the player passes the yellow checkpoint.
Awarded when the player defeats Chummy Bear.
Awarded when the player defeats the Alien Demon boss.
Awarded when the player defeats Deathbot.
Awarded when the player completes the game for the first time.
Awarded when discovering a secret room.