I will list them according to my general knowledge.

• In the first game, Jolly's jumpscare was changed in the 1.5 update while the others were left untouched for some reason.

• Speaking of Jolly's jumpscare, in the beta demo of the first game, There was an unused beta jumpscare of Jolly where his faceplates are less opened and his movement is less rotated.

• Speaking of the beta demo, Tweetie also has a beta jumpscare animation which was actually used in the demo unlike Jolly's.

• George is the only animatronic in the demo to have the same jumpscare animation across all iterations of Jolly 1.

• Maxie was never in the demo. It's possible that Maxie was added to have four animatronics like in FNaF 1.

• George was created by someone in DeviantArt as a FNaF OC, and IvanG used him for Jolly, making him the only character to not be made by IvanG.

• Tweetie's origins are fairly unknown, but it's possible that since Tweetie and Jolly performed "Birds and the Bees", it would make sense that there would be a bird character alongside Jolly who is a bee.

• There is a hidden screen which depicts the Puppet from FNaF 2 in millions of colours. Nobody even knew that screen even existed until this year where someone got the screen and posted it here.

• Cam 8 is kind of unnecessary, seeing as nobody ever uses the camera. That's because Metalionette was going to go there to attack the player until the wires mechanic was added.

• Jolly originally had an animation where he rises up and runs to your office, but it got unused for being too stupid for a FNaF fangame.

• Classic Jolly is known to appear in Night 4 without any warning, and jumpscare unsuspecting players with a seizure before crashing your game, but he can also rarely appear in other nights too. There is a YouTube video where he appears in Night 7.

• On some devices, in the mobile version of the game, because the code to close the game down doesn't work properly, Classic Jolly's jumpscare animation will play forever. This will force the player to restart the game.

• The game was released a mere three days before FNaF 5 came out.

• The creator used to be scared of Jollibee when he was younger, so that's what made Jolly exist.

• IvanG put in an easter egg of his previous fangame series, Five Nights in Minecraft. However it got unused for unknown reasons.

• Jolly 1's office looks fairly similar to FNaF 3's office, but it is reversed.

• The overall gameplay of Jolly 1 is like a mashup between FNaF 1, 3 and 5.

That's all for now.