Hello. Just want to ask why does my child object disappear when I press play? Cheers! 
that… depends? What’s the child object exactly?
Maybe it ran away? :eek:
Who are the parents? Where do each of them live?
Such a clickbaity title XD
From what he said, one of them is him. So propably one of them lives in Manila, Philippines;)
Maybe you should pay closer attention to where your child is at all times and not let them out of your sight. Children tend to be curious and may wander off without you knowing.
But seriously, what type of object is your child?
Typically child objects are not loaded into the game engine when:
A) it is of an unsupported object type (e.g. a curve object) - this is independent of the child relationship
B) if one of the parents is not available - either A) or it is at an inactive layer.
additional objects might exist but are not visible:
C) ensure it is not an alpha material
D) ensure the normals are pointing towards the camera
E) ensure the object is not rotated away (such as trackto, or halo-material)
F) ensure it is in the camera frustum volume (left, right, top, button, near, far) - it might be located somewhere else after starting the BGE
G) ensure it is not covered by other objects
H) When using armatures ensure the armatures bounding box is at least touching the camera frustum
…
Many options.
Hahahaha! Hilarious comments! I love it!
Basically, It’s the forestock of the shotgun. I parent it to the main body of the shotgun and didn’t actually made it as one object for animation purposes. Sorry, can’t provide the blend file right now because I’m still looking for the child. hahahah!
CHEERS!