Aside for the third level(there was no clue to a time based puzzle) they were all very good! However two minor things with this game.
First off, the graphics are kinda...eh, but understandable considering this was just a test. However the intro was completely unecessery, it was quite pointless as the game had nothing to do with it.

Just completed the game, loved the clues at the bottom which helped me to think outside the square, I like the simplicity of the game and the controls were easy (just dont overthink things).
A little confusing in some points, but again, I had to stop overthinking, and it was easy.

17 level is just so hard. I am not able to cross it at all. The gatherer level's down most circle is quite amazing. And also the bisect, mirror and constructing levels.

You should consider changing the colour of the background or the spirit ball, in some points it was difficult to see.

Not the most graphically amazing game, but it shows innovation in level and mechanic design.