Super Mario Bros. X Forums

I want to make a level where you have to kill all the bob-ombs to get a star, I’m 99% sure that I already know everything else I need to know but I can’t figure out where the "no more objects in layer" event is, i’m on SMBX2 by the way, all the other tutorials on how to do it is just outdated and from 5+ years ago.

That's not an event itself, it's a way to trigger events, and you can find it in NPC properties. Create an event for the star to appear, and set it as the no more objects in layer event in every bob-omb. This will make sure you will get the star once the layer is empty, because when a bob-omb is set up this way, the event will play if that bob-omb is the last one from the layer to die. You can also do this with various NPCs