Is it possible to do this?,if there was a possibility to do this in Mega Man for example,i would use it to make the Health Bars don't get inside the Level Blocks or something like that??
Sorry for my newbie english
the closest i've got is to be able to set text/gui stuff on the front layer, then setup the depth and zscale so the gui elements in question slightly "pop" over the rest of everything else. and while yes, that does mean that the GUI stuff is still inside level blocks, it's not being obscured. look at my megaman 2 or shatterhand 3dn's as an example (try metal man's stage for my mm2 3dn). not the best examples but it's the closest solution i have at this juncture.
Yeah, this is also a problem for Metroid. I initially tried doing the same as suggested above, selecting foreground and increase the zscale... imagine my surprise when I reset and saw the password screen. All numbers from 0 to 9 were stretched like crazy. And if I applied the same treatment to the missile icon missiles in-game would probably also get stretched like that.
Now with Metroid there's hardly any backgrounds at all, so it'd be possible to move everything except the meters to the background... but it just looks off.
So yeah, along with back and front it would be best to also have fore-front.
In fact, I'd take it a step further and add "far back" too, for those cases in which the sky is threated as an object (see level 3 of Castlevania or the background of the underwater levels in Mario).
Another simple example: for Donkey Kong, the ladders should be front layer, but need to be behind Mario and the other sprites. You can fudge it at the moment by giving Mario and enemies a larger width (e.g. ladder at 2 width, Mario at 4 width), but that's still not quite right.