Thanks newt.

I would prefer not to use the paste sprite trick but it seems to be the only way.

How can I draw transparency into canvas?

Like erasing parts of the image, the same as drawing with black or gray in the alpha channel.

Does a "no-color" color exists like the Overlay of MMF used to have that erase it?

*Note that I need to really erase the canvas texture by drawing, not just a cosmetic erase through shaders.

Don't know if it's a bug, probably more like an annoyance. The arcade page gets refreshed when you click to load another comment page, and the game restarts. If the game doesn't have any save system the player loose all the progress.

It would be better if only the comments updated, like YouTube.

You want to select only one of those 50 objects and make it visible, or you want to select all objects?

0plus1 you use a "Compare instance variable" condition for picking. I think you need to understand better how picking works, every event that reference an object is picking, not just the conditions that start with "Pick".

You can get more information here:

http://www.scirra.com/manual/75/how-events-work

Yes, it's possible to have the same functionality as a family tree, but you have to add each object individually to multiple families, instead of adding a family to another one (that would consequently add all the belonging objects automatically).

According to your explanation about constructors and destructors, they seem like an equivalent to the conditions "On object creation" and "On object destruction". There's no such thing in C2 yet, but I must say that would be very useful indeed.

Is it possible then to set the unique ID to something arbitrary?You can make an equivalent of an arbitrary unique ID by assigning a custom value or string to an instance variable. Then you can pick the instance by comparing the instance variable. It works the same as picking by UID. Just be aware that if there's more than one instance with that same value they will be picked as well.