Game is cute as a concept, very well polished and not as laggy as most commenters say (at least on a high end machine full of RAM), but the rapid notes at the end of the last song are not rhythm based. You don't really get to see or hear them, you just have to guess or learn where which note will happen. They jump out way too fast. It's a flash-reflex moment in a game that's otherwise about melody and rhythm and that throws me off
Collisions not working for me in the newest update, the cube goes through everything. On top of that, upon loading 3 last upgrade pads returned to "not bought" status (the 8K, 12K and 31K)
My suggestion is to keep your GUI consistent: when you have the interface based on the blue square interacting with buttons, either make "Load" and "Save" buttons away from the area the blue box operates in or (my personal preference) make it so the blue box can actually interact with them, like touch them or jump on them
 "Songbird Symphony v0.2"){kind=icon}
 "Cube It (Testing)"){kind=icon}
 "Astrox"){kind=icon}
When a new update comes out, loading often from a previous version often breaks it.