Thanks for the feedback. Tiles casting shadows is on the todo list, I take your point about how the dark side of the tiles suggests they should be there. The soft shadow under the robot is a bit of a cheat thing to actually get shadows to work and change shape as the robot moves up & down slopes, and across different height tiles. Might have to rethink that
I see what you mean about the triangle things on the bottom, they're a bit too bright on the lighter side.
The grey shades are nice, in fact the whole palette is, and yes grey is overused. I'll get more colour in to each level as the game progresses and more tiles are drawn. I feel these bright palettes work better when more colour is splashed about, it really brings to the graphics to life, even though such liberal use of bright colours puts me well outside my comfort zone.
Overall I do want to end up with an industrial feel, I wonder if the palette will allow for that?