Because FNaF is cool and edgy, it does not have achievements like other Steam games. Instead, FNaF World rewards its players with a series of decorative trophies whenever something of note is completed in-game. There are eight trophies in all. You can view them on the game’s loading screen between play sessions.
Security - Beat the Security boss. If you’re playing on Normal, it’s the final boss. If you’re playing on Hard Mode, it’s the second-to-final boss.
Scott - Defeat the final boss. You can only get this trophy on Hard Mode.
Chipper - Defeat Chipper’s Revenge. Chipper can be found in Mysterious Mine, through the northern entrance accessible via Lilygear Lake. He’s hidden in the shadowed area in the far west, and requires the Key to fight.
Freddy Legs - Speak to Fredbear with Fredbear in your party. He must be in the first position of your front (blue) party. Since you get Fredbear so late in the game, it’s easiest to start a new game after recruiting him, choose Fixed Party mode, put Fredbear in the party, and then proceed until you speak to the NPC Fredbear. (Which is... right away.)
Child - Get the clock ending. This requires completing a series of small minigames for a more sinister version of Fredbear. More details in this article. (And yes, it’s not in the screenshot above. The minigames keep freezing my game. Once I can complete the damned things I’ll post a new screenshot.)
Pixel Freddy - Get the ‘bad’ ending. To do this you must access the fourth layer of the Subtunnels, found in the final Subtunnel, just beyond the Circus Funhouse.
Pearl - Successfully grab the pearl five times at Deedee’s Fishing Hole in Fazbear Hills. (Be patient, it’s not as hard as it looks at first. Fish can cross your line, they just can’t touch the plunger.)
The Fan - Recruit all forty animatronics.