I was curious about this for a while, particularly as this is a compact puzzlescript game. When I finally realized what this is doing and how to play it, I really enjoyed the concept, especially the first time I saw that the player pushes the blocks to be executed, and that solving the puzzles therfore requires exploiting the left-right, top-down order of block processing.
Due to the graphics, it is not completely clear that the 3 blocks on the leftmost column are actually buttons and the next column are placeable blocks to be dragged onto the question marks. Therefore, I think some basic documentation would help more people appreciate this game. Even though there are only 3 levels, I really like the idea and enjoyed playing this game. Meta Robot indeed!
Maybe to open up some new level design ideas you can have experiment with different patterns of block processing. Moving in an inward spiral, all the way right - down - all the way left - down etc. Also a "breakpoint" would be good so when stepping you don't have to manually step past all the no-op blocks.