A partial list of the new Idle Game Maker features that I've seen:
- A system similar to Cookie Clicker's Reindeer mechanic (Seen in Bunny Clicker)
- Standardized sprite sizes (48*48, talked about in the new documentation; other sprite sizes may require a custom CSS)
- Sprite sheet system (Talked about in the game-making guide)
- A built-in import/export system (Noticed while playing Bunny Clicker)
- A full Info section w/ ability to write a game description (Noticed while playing Bunny Clicker; checked the game-making guide to confirm that, yes, every game has the option to edit it.)
- Improved default CSS (Achievements moved to Info, and upgrades moved to the far right; clickables displayed below. Also editable with a set of commands in the Layout section.)
- Probably more.