Very cool game! I enjoyed the visual style, first 2.5d i've played during this jam. I also enjoyed the mechanics; they were all very interesting and lays a great foundation for more levels.
One issue that i had was for the triangular ruler, the controls were kind of intuitive for me. I also flew it out of the screen, but because the controls were unintuitive to me I couldnt get it back LOL. Maybe either have a screen sized collision or have the ability to call the triangle back with a button press!