This was really nice :) The screenshots really drew me in, and I was not disappointed :D (However, there were no smily faces on the bubbles when I played, maybe you removed them after taking the screenshots?)
This was such an easy to grasp concept, and it just tickled my brain! The color palette switches were fantastic :D
The music, colors and effects were really pleasing, and I think going for a sphere “tank” was a great decision.
Also I didn’t realize you could tilt the tank, but I had fun nontheless :D