Spatial puzzles are already a favourite so I was excited for this one. I might've spent the most time so far on your game, puzzling out the levels and would've spent much longer if there were even more! Especially levels that have irregular shapes to fill like tangrams would be fun.
The perfect fit at the end has a high potential for satisfaction with a little more visual flair on the placements and some of that audio ssszzzshhhh(quiet click). I like that you went bold and industrial with the materials even if there wasn't time for fine tuning the glare, and think that some 2-3x chunkier shapes would fit even more with this design.