Thank you making this game. I played your game today (2017-05-07) and here are my thoughts:
* I appreciated the simple art style and the shadow effect on the 3D objects really made those objects stand out.
* I would recommend, at the very least, a scoring system so that players may appreciate their progress more.
* The explosions could have a different effect. Having the explosions use the same "shadow effect" as the enemies and other 3D objects make the explosions seem out of place.
Again, thank you for creating this game and I look forward to it's continued development.