Objects/Props observation

Not sure if this goes here, but I think it fits. There's something I've noticed when going through the objects/props. It seems a number of them have a thin black line at the top (not sure what this is called). Like the parallax of the city in the "rapture"(?) tileset. Plenty of tiles with transparency have it, and I just think it would be nice if it were adressed.

Here's a list, to make it easy to tell:
Salt Factory:
Steel Beam(Object)(Between fan and saw launcher)
Large Saw (Object)
Both Parallaxes (thin line)

Hell:
City Parallax (tint in transparency)

Rapture:
City Parallax (tint in transparency)

The End:
Bush Parallax (Tint in transparency)

8 bit:
City Parallax (tint in transparency)

There also seems to be a few tiling isuues with certain tiles. If any of this is intentional, or my settings are wrong (I believe everything is on recommended settings), then I will immediately delete this topic. These are just what I've noticed, and I thought it would should be brought to peoples' attention so maybe they can get fixed.

(still updating)