Sorry about the lack of sound. Implementing some sort of physics noise when things collide or indicators when you score/lose points or win a level would help a lot. The HUD bug it's definitely something I noticed and will fix for later release. Including a short tutorial even if it's a pair of infographic things could describe the goal of the game and the value system for pieces. If I can I'll include a way to make your own levels with .csv spreadsheets along with more levels.
Thanks for the awesome feedback! I'm glad that you liked it even with the shortcomings.